RECONSTRUCTION OF THE HISTORIC BATTLESHIP TEXAS

Transcription

1 RECONSTRUCTION OF THE HISTORIC BATTLESHIP TEXAS William M. Hayden, P.E. 1 (M), Allen Pac 1 (M), Julius M. Taylor, III 2 (M) 1. Waller Marine, Inc. Houston, TX 2. Taylor Marine Construction, Inc. Beaufort, NC Commissioned in 1914 as the most powerful weapon in the world, the Battleship TEXAS (BB-35) is the last surviving Dreadnought and the only battleship left in existence today, which fought in both World War I and World War II. Time and nature have taken a major structural toll on the ship; she is in immediate need of critical repairs, as well as a long-term solution for her continued preservation. Although a major shell restoration project was completed in 1990, the internal structure of the inner bottom has continued to deteriorate. In 2012, Texas Parks and Wildlife issued a Request for Proposals to solicit bids to perform an in-situ repair of the deteriorated frames, longitudinals, and inner-bottom plating. This phase of structural repairs is largely complete and has employed some novel techniques to restore the strength of the structural members while retaining as much of the historic fabric as possible. Additionally, the restoration presented an unusual scenario of needing to support the original tripleexpansion steam engines from overhead deck structure while renewing the foundation supports. This paper will describe the engine support system and the structural analysis used to design the system as well as details of the repair procedures to replacing or doubling the existing keel, longitudinals, and framing throughout the aft end of the ship.

2 KEY WORDS: Historic, Battleship, Reconstruction, Structure, Steam-engine, Analysis, Finite Element. INTRODUCTION Commissioned in 1914 as the most powerful weapon in the world, the Battleship TEXAS (BB-35) is credited with the introduction and innovation of advances in gunnery, aviation, and radar. She is the last surviving Dreadnought as well as the only battleship in existence today that fought in both World War I and World War II. After the end of World War II, she was de- activated and transferred to the State of Texas to serve as the first battleship memorial museum. Time and nature have taken a major structural toll on the ship. She is in immediate need of critical repairs, as well as a long-term solution for her preservation. Although a major shell restoration project was completed in 1990, the internal structure of the inner bottom continued to deteriorate. In 2012, the Texas Department of Parks and Wildlife issued a Request for Proposals to solicit bids to perform an in-situ repair of the deteriorated frames, longitudinals, and inner-bottom plating. The winning primary contractor was Taylor Marine Construction of Wilmington, North Carolina with Waller Marine, Inc. of Houston, Texas serving as the Engineer of Record. The structural repairs are currently underway and have employed some novel techniques to restore the strength of the structural members while retaining as much of the historic fabric as possible. Additionally, the restoration presented an unusual scenario of needing to support the original triple-expansion steam engines from overhead deck structure while renewing the foundation supports. This paper will describe the engine support system and the structural analysis used to design the system as well as details of the repair procedures to replacing or doubling the existing keel, longitudinals, and framing throughout the aft end of the ship. Prior to working under the main engines, their weight was to be suspended from above if possible. Waller Marine constructed a 3D SolidWorks model of the hull and internal structure around the engine rooms to determine how much and where the engine weight could be suspended. Prior to performing the finite element analysis it was necessary to determine the weight of each of the 100-year old triple expansion steam engines, which was not published in any available documentation. Once the engine weight was determined the task turned to how the engine's weight could be transferred from their foundations below to hull structure above. A system of bolt-on brackets and high-strength tension Dywidag rods were designed to support the weight from the armor deck. The system also included a real-time monitoring system to ensure that the supports remained within acceptable levels. Since the work was carried out with the ship afloat in its berth, two major challenges needed to be overcome to successfully re-frame her. First, a method had to be developed to renew steel members without causing damage to the hull due to the hydrostatic pressure loading present. The ship's draft is about 28-feet at the engine rooms, so that pressure was significant. In order to remove a frame for replacement, a temporary frame (or longitudinal or keel section) would be installed prior to removing the existing member. This method proved to be excessively time consuming, therefore a method was developed to sister the existing all-riveted members. The heavy steel angles originally used to rivet the plate frames to the shell and inner-bottom were, fortunately, still in very good condition compared to the framing members. New steel framing members were cut to fit just inside of the steel angle profile, and welded to it on each end with engineered brackets to develop full strength of the new frame member. Additionally, bolts were inserted along the center of the new member, bonding it to the existing member. The second challenge to overcome was the efficient delivery of the over 730 individual new steel pieces to the work site in the engine room alone (excluding the work performed in Space D- 12). This was accomplished by constructing an efficient fabrication facility, a sectional barge bridge, a road between the two, and a lift system to get the plate on the ship. An extensive monorail system with pneumatic chain hoists on rollers was installed inside of the ship to rig plate to the work site without the use of extensive bull rigging. Most pieces of steel were installed directly at the site with only two hook switches -one from the deck crane to either service room, and the other from the service room monorail hoist to the engine room lower level monorail hoist. Additionally, all steel plate was sand blasted and coated with a weld-through primer prior to Reconstruction of the Battleship TEXAS 2

3 delivery, which eliminated the need for abrasive blasting at the work area or on site. HOW HEAVY IS A STEAM ENGINE? Waller Marine, Inc. (WMI) has prepared a design to provide support for the main engines of USS TEXAS (BB35) during the completion of structural repairs to the inner-bottom structure below the engines. The support system consists of large plate steel brackets that attach to the engine support frames by means of bolted clamp connections. Steel rods are bolted to the brackets, extend upward and are fastened by throughbolting to the heavy plating of the Second deck. Strain gauges were fitted to each suspension rod as a means to measure rod tension and allow the tensioning of all rods equally. The strain gauges remained in place enabling continuous monitoring of support system loads for the duration of the innerbottom repairs. The proposed support system results in the least amount of disturbance or damage to historic structure. The bid solicitation issued by TDPW to complete reconstruction work on the TEXAS envisioned a system of cables run under each main engine and supported on the 3 rd deck by I-beam strong-backs. Our finite element structural analysis of the ship hull section has shown that the decks above the engine room of the TEXAS are incapable of supporting the full weight of the engines. Even with the addition of temporary bracing between the 2 nd and 3 rd decks, the maximum load we believe should be supported by the deck is 25% of the calculated engine weight. Anything greater than this will stress some structural elements close to their yield point. The original thought, to transfer all the weight of the engines to other ship structure may be somewhat moot at this point since the contractor is not proposing to crop out old steel in the bottom structure but to sister new material onto the old. We were not keen on transferring all the engine weight off the bottom structure as the external hydrostatic pressure may change the shape of the bottom structure and overstress the new steel when the weight is returned. The proposed arrangement provides the most reasonable balance to meet the intent of the project and provide an economical safety support system for the main engines versus an extensive and costly addition of temporary bracing. Figure 1 - Drawing of Main Steam Engine Taylor Marine Construction was the successful bidder and received a contract from the Texas Department of Parks and Wildlife (DPW) in response to the Project Number Structural Repair of the Battleship TEXAS State Historic Site. The specific paragraph from the solicitation regarding the engineered support system for the main engines is reproduced below: Design, detail and provide a temporary system of support for the triple expansion steam engine and thrust block. The system of support shall provide both vertical and lateral support for the main steam engine and thrust block. As shown in Figures 1 and 2, it is envisioned the support system can consist of a series of suspension slings supported from the armored deck above using rigid steel supports from the centerline wiring trunk and outboard bulkhead, and a series of steel plate brackets for lateral support of main engine, attached to the engine foundations. The main engines are estimated to weigh 1,100 long tons (2,464,000 pounds) each. Cable supports should provide a minimum safety factor of four (4.0) and should be tensioned (as verified by dial indicator gauges providing readout) to take the load of the engine off its substructure allowing repairs thereto be made in safety. Verify that existing ship structure onto which the engine weight is transferred is capable of sustaining this load in its present state. If needed for support scheme selected, provide strengthening of existing structure as required to sustain load. Submit for approval shop drawings of the proposed system and corresponding calculations, prepared and stamped by a Professional Engineer licensed in the state of Texas. Temporary support system must be completed and engaged before any work within the Inner Bottom tanks is started. WMI developed a safe and practical means of providing added support for the main engines of USS TEXAS (BB 35) during the repair of bottom structure in way of the engine foundations. The prioritized objectives associated with the Reconstruction of the Battleship TEXAS 3

4 performance of this work-scope are the safety of production workers and the ship, to provide a solution that has minimal impact to the ship and thus requires minimal restoration and lastly, to provide a reasonable, practical solution that is affordable. The bid solicitation documents contained a concept of a means to support the Main Engines while the innerbottom structure beneath the engines is repaired. Given that this concept was contained in the bid package, considerable thought was given to applying this particular approach. Considering that this particular configuration was the product of the combined efforts of marine surveying and licensed civil engineering consultants and embraced by TPWD it seemed prudent to make every effort to utilize this concept. However, fundamental issues stand in the way of a practical implementation of this plan. Wide Flange shapes (W-10x60) are indicated as the means to carry the load and provide local attachment points for the series of 2 cables that pass beneath the engine foundation and back to the beams. The Wide Flange beams will need to be considerably longer (and therefore much deeper and heavier) than presently indicated in order to completely bridge across the non-continuous deck beams in way of the engine removal soft patches and adequately transfer the loads to continuous transverse structure. The use of twenty two pairs of 2 cable loops would appear to provide flexibility in the routing of the cables but the bend radius of 2 cable is somewhat long and cannot make the hard bends as shown in the sketches of the suggested configuration. This arrangement would require a significant number of the cables (if not all of them) to be protected in way of the sharp bends around the engine foundation, that is, to incorporate a means of increasing the radius of the bend to an acceptable value, a requirement for which there is likely no practical solution. Moreover, it is neither clear what is to be considered proper tensioning of the cables nor how cable stretch would be addressed. WMI initially presented an alternative solution at early meetings with TPWD. This alternative consisted of attaching shackles to chocks in the cast iron engine foundation by boring holes through the chocks for the shackle pins. Cables would then be attached and run to existing structural brackets under the Third Deck at centerline on the inboard side of the engine and to structural brackets on the Second Deck directly above the outboard side of the engine. This approach was later rejected as it was determined that the boring of holes in the foundation itself would present an unacceptable risk to, and do irreparable damage to the cast steel foundation structure. This led to the consideration of the attachment of a fabricated fixture to the engine foundation by means of the existing (or new replacement) bolts that secure the foundation to the ship s bottom structure. The fixture would contain a pad eye to which a cable leading to the overhead could be shackled. As with the initial approach, it was felt that the cables could be run to existing structural brackets under the Third Deck at centerline on the inboard side of the engine and to structural brackets on the Second Deck directly above the outboard side of the engine. This configuration was then modeled in detail and analyzed with ANSYS finite element analysis software. Results indicated that the attachment fixture would have to be large and difficult to install and would require the removal and replacement of an extensive number of foundation bolts. Moreover, the ANSYS analysis results indicated that a significant amount of added stiffening would be necessary to give the brackets under the Third Deck adequate strength to accommodate the applied load. Further consideration indicated the need to revise the overall approach to engine support keeping in mind the key objectives of safety, producibility and affordability. An additional survey of the Engine Room led to the decision to make the connection to the engine by means of brackets attached with bolted clamps to the 6-inch diameter vertical members of the engine support frame. Two-inch steel rods replaced the original wire rope and the rods are run to the Second Deck. The rods penetrate the deck and are secured and tensioned by means of a nut on the threaded upper end of the shaft. Support rods were chosen over cable for a number of reasons, including the ability to handle shorter, i.e. lighter, lengths which can then be welded together on site to obtain the desired length; the ability to directly mount strain gauges to the rods; the ability to make a direct, welded, connection to the support bracket on the engine; and the ability to control the load capacity through alloy material selection. LOADS AND SAFETY FACTORS The loads were established after a careful weight estimate was prepared. All major components were considered from a conservative perspective. An initial estimate was prepared by Taylor Marine which Reconstruction of the Battleship TEXAS 4

5 was then checked and augmented by Waller Marine. The weight of the components to be supported was calculated to be 550 tons. The value of 550 differs considerably from the 1100 tons published in the original bid documents. The difference lies in the methodology for the determination of the engine weight. The 550 tons determined by carefully reviewing drawings of the engine and foundation and to rigorously consider each component individually and to conservatively estimate all major components including the addition of conservative assumptions for lesser items and for miscellaneous items for which detail is not provided. This method is often considered needlessly tedious in comparison to a theoretical approach but in this situation the theoretical approach will (and has) produced too coarse a result for the following reasons. Starting with the most recently established lightship weight for BB 35 which was likely determined to support the preparation of the Stability Assessment in early 2011, one could theoretically deduct the weight of all other components of the ship besides the engines leaving the resulting balance to represent the engine weight. The difficulty with this approach is having or deriving accurate weight values for all other components besides the engines. It may have been possible to find original weight data that would have included the engine weight but this was just not available. An attempt to estimate the other weight elements of the ship would still be too coarse an approach since any unknown items of weight growth due to ship alterations, etc. would end up in the remaining balance representing the engines. This would also be true of any unidentified items of deadweight such as un-quantified liquids in tanks, excess spare parts and tools and any other consumable items not identified and deducted. The weights of these items would then contribute to an excessively conservative resultant representing the engine weight. It should be noted that in the naval ship engineering life-cycle support community, steady and significant lightship weight growth is commonly observed over the life span of a naval surface combatant. The bid documents indicate that a factor of safety of 4 should be applied to all of the elements of the support system. Those working in the shipbuilding and construction industries recognize that rigging components such as shackles and slings are rated for use by the manufacturer on the basis of this safety factor. This practice is intended to be very conservative because these components are used for overhead lifting and it is intended to address many unknowns and uncertainties. The manufacturer cannot be present to assure that riggers are lifting items for which they have very accurate weight data. They also cannot guarantee that a suspended load will not be allowed to free fall and then be suddenly checked with the brake resulting in additional dynamic loading. The manufacturer is not present to inspect the material condition of the rigging components to assure there is no damage or deterioration due to age, misuse or poor maintenance. The manufacturer is not able to assure that in all cases those using their product will be properly trained in the use of these products. Thus, as rigging components are typically used for overhead lifting manufacturers must be concerned about potential liability. While the bid documents suggested that the engines shall be suspended while all deteriorated structure beneath is cropped out or completely removed and later replaced, the Taylor Marine procedure is to overlay or sister existing inner-bottom structure with new material. The only removal will be strips of tank top plating in limited increments to allow the insertion of new material into the inner-bottom space. This will be done methodically and incrementally with existing openings being closed once the local repairs are complete before new openings are cut to allow work to continue in the next adjacent section of inner-bottom. During this procedure the engines will in no way be a suspended load but rather will have added support to offset any unexpected reduction of ship structural support under the engines. It was recommended that a structural monitoring system be installed as part of the overall engine support scheme. The ship support system will include strain gauges on each of the steel suspension rods and the loads will be reported and recorded on a PC located adjacent to the engine rooms. The monitoring will be done on a continuous basis for the duration of the repair effort and until the support system is no longer required. The rods will be tensioned be means of tightening the nuts on the upper ends of the rods and the strain gauge readings will provide indication of the load on each rod, allowing the rods to be tensioned equally and to the specified value. Among the objectives of this effort is affordability and excess conservatism nearly always results in a Reconstruction of the Battleship TEXAS 5

6 more robust solution which in turn drives costs upward. The plan for the tensioning of the rods is to load them to a value of 25% of the calculated load. This is planned as there is no intent to attempt to lift the engine. Results of the structural analysis indicate that this is feasible but with a factor of safety of It should be noted that in shipbuilding practice, many ships with intended life-spans of 20 to 30 years are designed with structural factors of safety of 1.7. Considering the controlled conditions under which this repair effort is being conducted, a factor of safety of 1.25 is reasonable, especially in comparison to a ship at sea over a 20 to 30 year lifespan. Analysis further indicates that to support a significantly greater portion of the engine weight will require the addition of a considerable amount of temporary structure to the ship to a degree that is not feasible for this effort. STRUCTURAL ANALYSIS This section presents the results of the various finiteelement structural analyses performed to develop the engine support system beginning with engine bracket and progressing logically to the effect on the ship structure as a whole. Characteristics common to all the analysis are shown below. Coordinate System The axes of the coordinate system used for the analysis are as follows: + (Positive) X is Forward + (Positive) Y is Upward + (Positive) Z is Right or starboard Mesh Meshing of solid models was done with the relevance center set at fine and with smoothing at medium. The method of element generation was set as tetrahedrons for all components. Meshing of shell models was done with the relevance center set at coarse and with smoothing at medium. Material and Allowable Stress Allowable stress was determined to be 0.8 times the material s minimum yield strength, and thus equating to the previously determined safety factor of ASTM A-36 structural steel was assigned for all plate and pipe components of the engine support fixture. The minimum yield strength of ASTM A-36: Standard Specification for Carbon Structural Steel plates, shapes, and bars is 36,000 psi. The mechanical properties of ASTM A-36 are presented in the table below. ASTM A-36 Plates, Shapes, and Bars Elasticity 29,000,000 psi Poisson's Ratio 0.3 Min. Yield Strength 36,000 psi Allowable Stress (1.25 F.S.) 28,800 psi Table 1 - Mechanical properties of ASTM A-36 Since the material of the engine support legs is not identified on any of the drawings we needed to make an educated assumption as to the material properties in order to perform the analyses. From the reasonably fine surface finish and the changes in cross-section for the bracing attachments, we are surmising that they are made of some form of wrought steel rather than cast steel. The standard we believe can reasonably be applied is ASTM A-41: Standard Specifications for Refined Wrought-Iron Bars (Withdrawn) with the below mechanical properties. ASTM A 41 Bars Elasticity 28,000,000 psi Poisson's Ratio 0.28 Min. Yield Strength 25,000 psi Allowable Stress (1.25 F.S.) 20,000 psi Table 2 - Mechanical properties of ASTM A 41 ABS Grade-A steel was assigned for all plating and structural members within the modeled portion of the Battleship Texas we found that this value was more conservative than what was normally specified (Holms, 1908). The minimum yield strength of ABS Grade A steel (34,000 psi) is from ABS Steel Vessel Rules Part 2: Rules for Materials and Welding, Chapter 1, Section 2. The mechanical properties of ABS Grade A are presented in the table below. ABS Grade A Elasticity 29,000,000 psi Poisson's Ratio 0.3 Min. Yield Strength 34,000 psi Allowable Stress (1.25 F.S.) 27,200 psi Table 3 - Mechanical properties of ABS Grade A Applied Loads Although the solicitation indicated that it was desired to transfer 100% of the engine weight to other ship structure, this was not in the best interests of the ship and as we discovered later unreachable. Our initial goal was to design a system capable of supporting 50% of the engine weight with a safety factor on yield of greater than 2.0 so it could support the full load under catastrophic circumstances. Reconstruction of the Battleship TEXAS 6

7 The load applied to the modeled engine support fixture was determined by dividing one-half of the calculated engine weight (275 tons) by the total number of support fixtures to be used in the support operation (12 fixtures) for a per-support load of 45, pounds. This load, conservatively rounded up to 46,000 lbf, was applied in the +Y direction and located on the top sectional surface of the modeled segment of suspension rod. Standard earth gravity of in/s 2 was applied for all modeled components, in order to account for stress contributed by their self weight. ENGINE SUPPORT FIXTURE Arrangement and Model A solid model of the designed support fixture was constructed using SolidWorks; lifting pad eyes and tripping brackets were omitted as they were determined to be unnecessary for the analysis due to greater computation time and less conservative stress results. The model was exported from SolidWorks as Parasolid format and then imported into ANSYS Design Modeler for geometry processing. Within Design Modeler, all components of the support fixture were grouped in one multi-body part and thus shared typology between contacting components was insured. The modeled geometry is shown in the Figure 4 below. Results The results from the engine support fixture analysis showed von-mises stress being less than the allowable stress of 28,800 psi for the vast majority of the modeled components (see Figure 3). The highest stress of 41,235 psi occurred in the upper corner of the top most 5/16 inch fillet weld that connects with the suspension rod. Since this highest stress was located within the weld, which is comprised of electrode material with higher yield strength than the base steel, the allowable stress of 28,800 psi was not applicable in determining its integrity. The stress within the weld becomes acceptable when the weld material meets or exceeds ASTM E60xx electrode with minimum yield strength of 52,000 psi and using a safety factor of Based on the results of the analysis, the engine support fixture is adequately designed in resisting the applied loads. All plate and pipe members of the support fixture experienced stresses less than allowable. Figure 2 - Modeled geometry of engine support fixture Mesh A general element size of 0.50 inches was utilized for the overall model. However, regions expected to experience elevated stress results, such as within welds and suspension rod, were further refined to a smaller element size of inches. The mesh for this item has 962,024 nodes and 657,892 elements. Constraints The model was constrained by applying fixed supports onto inner surfaces of the two clamping pipe sections. Figure 3 - Von-Mises stress of engine support fixture ENGINE SUPPORT FIXTURE AND BRACING Arrangement and Model A transverse section of the engine foundation along with the two 6-inch diameter vertical engine frame members, the attached clamping support fixtures, and cross bracing were modeled in SolidWorks. Both support fixtures were aligned perpendicular to the centerline of the engine foundation. The model was exported from SolidWorks as Parasolid format and then imported into ANSYS Design Modeler for geometry processing. Within Design Modeler, all components belonging to the two engine support fixtures were grouped in one multi-body part and all components of the engines support structure were grouped into another multi-body part. Within each multi-body part, shared typology will be insured between contacting components. Reconstruction of the Battleship TEXAS 7

8 Figure 4 - Modeled Geometry Engine Support Fixtures and Engine Bracing Coordinate System For the purposes of this analysis, the origin was placed at the base level of the engine foundation and centered between the two circular bolting flanges of the 6-inch vertical members. Mesh A general element size of 1 inch was utilized for the overall model. Surfaces on the 6-inch diameter vertical members, that will be in contact with the clamps of the engine lift fixture, were further mesh refined to an elements size of 0.25 inches. The highest stress was expected in these surfaces and thus it was advantageous for the assignment of a finer mesh size. The mesh for this model has 950,286 nodes and 548,095 elements. Material ASTM A 41 wrought iron properties were assumed for components of the engine support frame. ASTM A 36 structural steel was assigned for components of the engine support fixtures. Loads and Constraints Load applied onto each of the engine support fixtures was determined by dividing one half of the calculated weight of the engine (275 tons) by the total number of support fixtures to be used in the supporting operation (12 fixtures). This load of 46,000 lbf was applied in the +Y direction and at each one of the modeled tension rod s top sectional surface. Loads applied onto the engine foundation and the two 6- inch diameter vertical members were determined from dividing the full calculated weight of the engine (550 tons) by the number of transverse foundation segments (6 segments). This load of 184,000 lbf was then distributed with 30% (55,200 lbf) on the top surfaces of the engine foundation section and 70% (128,800 lbf) on the top bolting flanges of the 6-inch diameter vertical members. The inner surfaces of support fixture clamps are bonded onto contacting surfaces of the 6-inch vertical members. Frictional contacts were investigated and deemed unnecessary for the analysis; the usage of a frictional nonlinear analysis increased the computation time by an order of magnitude and produced nearly identical stress results, compared with the bonded linear analysis. The model was constrained by applying fixed supports onto bottom surfaces of the engine foundation section. Cylindrical support with free axial displacements (Y direction) was set at the top flanges of 6-inch diameter vertical members, in order to maintain the constant distance of separation. The loads and constraints aforementioned are presented in Figure 5 and Figure 6 below. Figure 5 - Applied Loads Figure 6 - Applied Constraints Results The majority of the engine foundation, 6-inch diameter vertical members and bracing, experienced von-mises equivalent stresses less than 10,000 psi (see Figure 7). All elevated stresses were located at where the surfaces of 6-inch diameter vertical members were in contact with the top and bottom corner edges of the support fixtures clamps. These stress risers when calculated within a linear ANSYS analysis are characterized by Reconstruction of the Battleship TEXAS 8

9 unrealistically high elevated stress values that are confined to small regions and with rapid decrease in stress intensity. For this analysis, stress results that were above allowable stress will be considered as acceptable, if the aforementioned stress was no greater than 1.25 times the material s yield strength and the stress gradient at a distance of 1 inch away were below the allowable stress. This is consistent with guidance published by the American Bureau of Shipping (ABS, 2014). The maximum stress of 23,571 psi occurred on the vertical member surface corresponding to the top stress riser region of the right (+Y) facing support fixture (see Figure 8). Although this maximum stress was greater than the allowable stress of 20,000 psi, the stress was considered acceptable since stress results decreased to below allowable stress at a distance of just 0.25 inches away. Figure 7 - Stress in Engine Foundation and Bracing Figure 8 - Max stress in 6-inch diameter vertical member ENGINE SUPPORT AND BRACING WITH FIXTURE ROTATED 45 DEGREES Arrangement and Model It was recognized in arranging the engine support fixtures that several may need to be rotated away from perpendicular to avoid interferences with ship structure or engine appurtenances. Therefore, an additional analysis was performed with one bracket rotated to the maximum of 45-degrees off-axis to determine if the engine frame was being overstressed. The modeled geometry is shown in the Figure 9 below. Figure 9 - Modeled geometry engine support fixtures and engine bracing Results The majority of the engine foundation, 6-inch diameter vertical members and bracing experienced von-mises equivalent stresses less than 15,000 psi (see Figure 10). All elevated stresses were located at where the surfaces of the 6-inch diameter vertical members were in contact with the top and bottom corner edges of the support fixtures clamps. These stress risers, when calculated within a linear ANSYS analysis, are characterized by unrealistically high elevated values that are confined to small regions and with rapid decrease in stress intensity. In reality, reasonably high stresses in sharp corners of ductile material are relieved by localized yielding and with near negligible effects on the integrity of the overall structure. Also, it needs to be noticed that the designed support fixture will have beveled edges around the inner clamp corners and thus stress within the aforementioned stress riser regions will be greatly reduced. For this analysis, stress riser results that were above allowable stress will be considered as acceptable, if the aforementioned stress was no greater than 1.25 times the material s yield strength and the stress gradient at a distance of 1 inch away were below the allowable stress. The maximum stress of 32,183 psi occurred on the vertical member surface corresponding to the top stress riser region of the 45 degrees angled support fixture (see Figure 11). Although this maximum stress was greater than the allowable stress of 20,000 psi, the stress was considered acceptable since its value was less than 1.25 of yield (31,250 Reconstruction of the Battleship TEXAS 9

10 psi) and stress results decreased to below allowable stress at a distance of 0.50 inches away. Based on the results of this analysis, all modeled structures of the engine support and foundation will be adequate in resisting the applied loads. transfer of load onto the designed engine support fixture. Figure 12 - Von-Mises stress of revised engine support fixture Figure 10 - Stress in engine foundation and bracing Figure 11 - Max stress in 6-inch diameter vertical member REVISED ENGINE SUPPORT FIXTURE The low stress and deformation results from the previous engine support fixture analysis showed that the original design was over-engineered for the applied load of 46,000 lbf. The thickness of the bracket plates could be reduced while still achieving stresses well below the allowable. It was therefore decided that plate thickness reductions to ¾ inch for the vertical plates and ½ inch for the two horizontal plates would be investigated with ANSYS. Also, the revised engine support fixture would use 1 inch diameter threaded tension rods that are held in place by anchor plate and hex nut, instead of the previously analyzed 2 inch diameter suspension rod attached by fillet and slot welds. The threaded tension rod, anchor plate and hex nut are rated by the manufacture for a load greater than the applied load of 46,000 lbf and thus stress results within these components were not analyzed for structural integrity. These components were modeled purely to insure accurate Figure 13 - Maximum Von-Mises stress 50% ENGINE LOAD Arrangement and Model The Battleship Texas was constructed in SolidWorks as a shell model spanning from Frame 89 to Frame 104 and from baseline to the armor deck. All major plating and stiffening members were included in the model. However, brackets other than those located on the centerline bulkhead and engine thrust foundations were omitted as they were deemed unnecessary for this analysis. Simplifications to the model were made in order to produce conservative stress results. All transverse c channel stiffeners underneath deck plating were modeled as L angles by omitting the top flanges in contact with deck plating. All vertical c channel stiffeners of longitudinal bulkheads and between deck side shell plating were modeled as flat bars by omitting both flanges. Stanchions on the second deck were assumed to be size 5 schedule 40 pipe. The model was exported from SolidWorks as Parasolid format and then imported into ANSYS Design Modeler for geometry processing. All shell bodies were grouped into one multi-body part and thus insuring share typology. The modeled geometry Reconstruction of the Battleship TEXAS 10

11 is shown in Figure 14 and Figure 15 below. Figure 14 - Modeled portion of Battleship Texas plating, bulkheads and longitudinal girders. The calculated stress results indicated that the modeled portion of the Battleship Texas cannot safety support 50% of the engine s weight (550,000 lbf) when loaded at both port and starboard side of the armor deck. Stresses within the armor deck plating and second deck plating were acceptable. However, second deck transverse stiffeners that are connected to centerline brackets and terminating on hatch openings experienced von-mises stress greater than yield strength of ABS Grade A (34,000 psi) across large regions of their span (see Figure 20). Some of these stiffeners recorded stress values exceeding 60,000 psi. Figure 15 - Modeled portion of Battleship Texas with decks and hull plating hidden LOADS AND CONSTRAINTS Two force loads, with both equaling to 50% of the engine weight (550,000 lbf), were applied onto the armor deck plating (see Figure 17Figure 17 - Force loads applied onto armor deck). The first force load was applied onto the 12 suspension rod deck attachment points on the starboard side and likewise the second force load was applied to the 12 suspension rod deck attachment points on the portside. These attachments points were represented on the armor deck as 12 diameter surface regions. The top plate surfaces of each engine trust foundation were applied with a force load equaling to 50% of the engine weight (550,000 lbf). All force loads acted in the Y direction. A hydrostatic pressure representing seawater was applied to the side shell and bottom shell (see Figure 19). The free surface of the seawater was set at an elevation of 25 feet above baseline. The density of seawater was set as 64 lbm/ft 3. Fluid acceleration was applied equaling to standard earth gravity ( in/s 2 ) and acting in the Y direction. The model was constrained by applying fixed supports on forward and aft edges of continuous Figure 16 - Locations armor deck rod attachment points on starboard. Portside similar but opposite hand. Figure 17 - Force loads applied onto armor deck Figure 18 - Force loads applied onto engine thrust foundations Reconstruction of the Battleship TEXAS 11

12 Figure 19 - Hydrostatic pressure Results The calculated stress results indicated that the modeled portion of the Battleship Texas cannot safety support 50% of the engine s weight (550,000 lbf) when loaded at both port and starboard side of the armor deck. Stresses within the armor deck plating and second deck plating were acceptable. However, second deck transverse stiffeners that are connected to centerline brackets and terminating on hatch openings experienced von-mises stress greater than yield strength of ABS Grade A (34,000 psi) across large regions of their span (see Figure 20). Some of these stiffeners recorded stress values exceeding 60,000 psi. Figure 20 - Stress at second deck stiffeners connected to centerline brackets The maximum stress in the entire model occurred in a stress singularity at where the starboard pipe stanchion was attached to the transverse stiffener underneath the armor deck. This singularity was due to the limitation of using 2D shell elements to connect the circular pipe with the straight edge of the stiffener s web. The edge of the stiffener s web intersected the circular pipe at two points and thus all forces transmitted on to the top of the pipe stanchion only passed through these two points. Every pipe stanchion in the model will each have two stress singularities. Results in stress singularities are unrealistically high by nature and were disregarded in this analysis. Stresses located 2 inches away from the maximum stress value rapidly decreased to around 25,000 psi. With stress singularities disregarded, stanchions on both starboard and port side along with their connecting armor deck stiffeners were deemed acceptable to the applied loads. The outboard pointing corners of brackets on top of the centerline wire duct had stresses greater than the allowable stress of 27,200 psi. However, because these elevated stresses were located in sharp reentrant corners and stress values decreased to below allowable at distances less than 2 inches away, they were considered as acceptable. Figure 21 - Stress in bracket on top of centerline wire duct 50% ENGINE LOAD PLUS CENTERLINE STANCHIONS It was recognized from the analysis above that stresses in the yielding second deck stiffeners could be relieved if force loads applied onto the armored deck were directly transferred into the centerline bulkhead plating. Arrangement and Model It was decided that temporarily pipe stanchions positioned between second deck and armor deck, and aligned with centerline would be a viable solution in achieving the desired stress reduction. These centerline pipe stanchions were added into the Solidworks shell model at locations spanning from Frame 90 through to Frame 102. The model was exported as Parasolid format and then imported into ANSYS Design Modeler for geometry processing. All shell bodies were grouped into one multi-body part and thus insuring shared typology. Results With the addition of the temporary centerline stanchions, stresses decreased to around 42,000 psi in the second deck stiffeners attached to centerline brackets. However, these stress results remained above the allowable stress of 27,200 psi across Reconstruction of the Battleship TEXAS 12

13 substantial portions of their spans and were thus deemed unacceptable for the applied loads. Figure 22 - Stress at second deck stiffeners connected to centerline brackets Stress values in stress singularities of centerline stanchions were disregarded. All stress results 2 inches away were below that allowable stress of 27,200 psi. Therefore, it was determined that the centerline stanchions and the connection armor deck stiffeners were acceptably stressed from the applied loads. Similarly, stanchions in both port and starboard side were also acceptably stressed. The outboard pointing corners of brackets on top of the centerline wire duct had stresses greater than allowable. However, because these elevated stresses were located in sharp re-entrant corners and stress values decreased to below allowable at distances less than 2 inches away, they were considered as acceptable. Figure 23 - Stress in bracket on top of centerline wire duct 25% ENGINE LOAD Stress results for the previous analysis showed that the addition of centerline stanchions was not adequate in reducing stresses to below allowable when the armor deck was loaded to 50% of engine weight. In order to achieve acceptable stress results within the second deck stiffeners, the loads applied onto the armor deck were reduced to 25% of the engine weight. The first force load was applied onto the 12 suspension rod deck attachment points on the starboard side and the second force load was similarly applied to the 12 suspension rod deck attachment points on the portside. Results All stresses within the previously yielding second deck stiffeners became less than the allowable stress of ABS Grade A steel (27,200 psi) when the armor deck was loaded on port and starboard side with 25% of the engine weight. 25% ENGINE LOAD ON 6 ARMOR DECK ATTACHMENT POINTS One additional case was investigated to see if the number of suspension rods attached to each engine could be reduced. Results from the previous analysis showed that the modeled portion of the Battleship Texas, with the addition of temporary centerline pipe stanchions, could adequately withstand simultaneous loads equaling to 25% of the engine weight when applied onto the 12 suspension rod attachment points located on both port and starboard side of the armor deck. Loads and Constraints Two force loads with both equaling to 25% of the engine weight (275,000 lbf) were applied onto the armor deck plating. The first force load was applied onto the 6 suspension rod deck attachment points on the starboard side and the second force load was similarly applied to the 6 suspension rod deck attachment points on the portside. The locations of these attachment points are identified in Figure 16 by the numbered tags 1, 2, 7, 8, 11 and 12. The top plate surfaces of each engine trust foundation were applied with a force load equaling to 75% of the engine weight (825,000 lbf). All force loads acted in the Y direction. Results The second deck stiffeners that were connected with centerline brackets had stress results less than the allowable stress of 27,200 psi. The reduction in the number of armor deck attachment points from 12 to 6 did not produce any drastic increase in stress intensities. Stress results within these stiffeners increased no more than approximately 1600 psi when compared to the previous analysis with the 12 attachments points. However, it needs to be noticed that a few of the second deck stiffener are approximately 100 psi away from reaching the allowable stresses. Reconstruction of the Battleship TEXAS 13

14 Figure 24 - Stress at second deck stiffeners connected to centerline brackets Figure 25 - Stress in starboard side stanchions Engine thrust foundations, frames and grillage remained lightly stressed. The majority of these structures experienced stress results less than 10,000 psi Figure 27 - Illustration of Engine Suspension System (Looking Aft at Port Steam Engine) Figure 26 - Stress in engine thrust foundations, frames and grillage Each rod was fitted with a pre-calibrated magnetic permeability sensing tension sensor. All 12 sensors fed into a signal multiplexer installed on the main deck of the ship. The data (displayed in kips for each of the 12 rods) was wirelessly transmitted to the Taylor Marine mobile office adjacent to the ship for monitoring. Based on the results of this analysis, all modeled structures of the Battleship Texas are sufficient to support the applied loads. Prior to working under the steam engines, their weight was to be suspended from above. Dywidag Systems International (DSI) was contracted to develop a system to monitor the load on each suspension rod in real time while work was ongoing. This system would alarm if one or both of the 550-ton engines started to settle, or if the 2nd Deck started collapsing. Once the system was installed and operationally tested, cutting in the engine room could begin. Engine Suspension System Data Analysis After the Engine Suspension System (ESS) was fabricated and installed, the DSI Rod Tension system was aligned, the rods tensioned and the data recording system started and monitored. 6 each 1 diameter DSI Threadbar rods, tensioned to 40 kips each supported each engine. Figure 28 - DSI DYNA Force Tension Sensor Waller Marine and TMC invested significant effort to minimize physical interferences between the ESS and the existing structure, and the installation went smoothly and faster than predicted. Each of 12 brackets were custom fabricated with a lever arm length tailored to the details of interferences at each location, not to exceed the design length by Waller Reconstruction of the Battleship TEXAS 14

15 Marine. Also, the brackets were rotated as necessary to minimize vertical interference issues while remaining within the Waller design stress limits. Figure 29 - One of 12 Installed ESS Brackets with DSI Threadbar Attached The initial data monitoring protocol was to monitor the tension in each of the 12 rods and ensure that the tension in each rod remained within 5% of its initial value. If the tension were to rise in a rod or group of rods, it would be implied that the engine was settling down into the framing, and work would be stopped and a shoring plan established. If the tension were to lower in a rod or group of rods, it would be implied that the second deck (attachment point for the ESS rods) was settling, and work would be stopped and a more robust 2nd Deck shoring plan would be implemented. This would have been a very simple, effective system, but it was immediately obvious that this plan was not to be. The forces measured in each of the rods varied by as much as 4 kips throughout the day. location of Battleship TEXAS in the Houston Ship Channel is affected the normal lunar tide cycle in the Gulf of Mexico, and by sustained wind direction since it is approximately 35 miles from Galveston Inlet up Galveston Bay and the Ship Channel. As shown in Figure 30, each rod s tension tracked together as the bottom of the ship flexed upward during lower tides, and lower during higher tides. Additionally, on days with a sustained and strong northerly wind, the tide level fell and stayed low, and the ship came visibly out of draft, which validated the pluff mud explanation. A new approach was developed and data was normalized each week, and a maximum and minimum baseline was established. No unusual deviations in tension occurred throughout the life of the project. PRODUCTION The first major challenge was the efficient delivery of new steel to the work site since over 730 individual pieces of steel plate had to be installed consisting of 3/8 thick A-36 steel plating for new framing, ½ thick A-36 steel plating for longitudinals and bulkheads, and ¾ thick A-36 plating for the keel. This was accomplished by constructing an efficient fabrication facility, a sectional barge bridge, a road between the two, and a lift system to get the plate on the ship. An extensive monorail system with pneumatic chain hoists on rollers was installed inside of the ship to rig plate to the work site without the use of extensive point-to-point chain fall bull rigging. Most pieces of steel were installed directly at the site with only two hook switches one from the deck crane to either service room, and the other from the service room monorail hoist to the engine room lower level monorail hoist. Additionally, all steel plate was sand blasted and coated with a weld-through primer prior to delivery, which eliminated the need for abrasive blasting at the work area or on site. Figure 30 - ESS Rod Tension for a Typical Week After careful review and crosschecking of tidal data, it was discovered that the ship was sitting in pluff mud (silt) and that the level of tide significantly affected the tension in the ESS rods. Tide level at the Figure 31 - Sectional Barge Bridge to Ship Reconstruction of the Battleship TEXAS 15

16 Figure 32 - Temporary Steel Cutting and Fab Shop The next challenge was to remove interferences to allow access to the tank tops and work area. Of note, each item removed was required to be re-installed as found, so TMC implemented a detailed Artifact Control System to document removal, tag each time, and ensure that each tagged item would be put back as found. First, ventilation system fans and bomb guards were removed in the service rooms to each engine room. Bomb guards are heavy steel grating assemblies constructed from 1 x 6 flat-bar, edge up, 6 apart, spanning ventilation ducts. Their purpose was to force a dropped bomb or shell to explode in the very upper portion of armor deck openings, such as ventilation ducts or access hatches in this case. This would minimize damage in the vital equipment rooms below the armor deck. Next, all of the lower level deck plates (over 200 of them per engine room) and their supporting framing were removed to allow access to the engine room piping below the deck plates. The engine room piping removal was risky due to the possibility of hydrogen sulfide gas accumulation in the old fuel and oil piping. A system of ventilating and monitoring each joint with a 4-gas analyzer was implemented, and all 260 joints of engine room piping were removed in each engine room, rigged out and stored. Figure 33 - Engine Room Piping Interferences Once the ESS was operational, and after the fuel tanks were all cleaned and certified safe for hot work, the tank tops were cut out between longitudinals to allow access to the existing longitudinals (keel) and framing, as seen in Figure 34. As shown in Figure 35, there were 10 sections between longitudinals to be worked. No two sections were ever worked side by side to minimize hull deflection while conducting the repair method. When one section was completed, that section s tank top (1/2 new plate) was reinstalled prior to cutting out the tank top in the next section. This maximized hull strength during the repairs, since the tank top contributed to that strength. Figure 34 - Section Shown with Tank Tops Removed, Exposing the Bottom of the Ship Immediately after tank top removal in each section, the tank bottom was cleaned of debris and mud from previous flooding events. The mud was clay-like and was from 6 to 12 thick. Additionally, the ship s bottom was paper-thin in many areas due to general and galvanic corrosion over the century old life of the hull plating. An employee dropping something as trivial as a chipping hammer presented a major risk of flooding in the engine rooms (the largest spaces on the ship). Once cleaned, TMC installed a product originally intended for soil erosion control, fit to the dimensions between each frame and longitudinal on the very bottom plating of the ship. Manufactured by Milliken and Company, this material named Concrete Cloth was supplied in bulk rolls, and was ½ thick concrete impregnated cloth with a strengthening fiber integral to it. Once fit and installed, it was cured with water and formed a ½ thick concrete protective layer to minimize the risk of introducing a leak in the extremely thin bottom. This step was instrumental in minimizing the chances of holing the bottom of the ship during the repair work, and no holes were introduced to the hull during work. Reconstruction of the Battleship TEXAS 16

17 REPAIR METHOD Since the ship was floating in a slip and not in a drydock, two major challenges had to be overcome to successfully re-frame the ship while she was floating. First, a method had to be developed to install new steel members without causing damage to the hull due to the hydrostatic loading present. The ship s draft is about 28 feet at the engine rooms, so that pressure is large (1860 lbs. psf). In order to remove a frame for replacement, a temporary frame (or longitudinal or keel section) would have to be installed prior to removing the existing member. This method would have been excessively time consuming, therefore a method was developed to double the existing members. The ship was built between 1909 and 1912, well before welding technology was practical, therefore she was of riveted construction. Most 90 degree joints, such as keel to shell plating, longitudinal to shell plating, and frame to shell plating were made up using a heavy section of steel angle as a corner. The angle section used in the engine room repair area was either ½ x 5 x 5 or ½ x 3 x 5. Fortunately, most were still in very good condition compared to the framing plate. New steel framing members were cut to fit just inside of the steel angle profile, and welded to it on each end with engineered brackets to develop full strength of the new frame member. Additionally, four bolts were installed in the center of the new member, bonding it to the existing member. Each of the two side-by-side Engine Rooms contained three fuel tanks six total. Contract tasking was to repair the keel, longitudinals, framing, and water tight bulkheads with the tankage from Frame 89 to 104 (the forward and aft bounds of both engine rooms) and from the keel out to longitudinal number 5 on each side of the keel. The following sequence of figures illustrates the repair method used to notch existing framing, install new longitudinal (or keel) sections, and framing. Prior to notching the existing frame for new longitudinal steel installation, Waller Marine performed Finite Element Analysis to determine the effect of notching the framing on hull strength. Waller determined that 3 adjacent frames on the same side of a longitudinal could be notched without damaging the ship. TMC imposed a control limit of 2 notches maximum while installing new longitudinals. This provided further margin from failure and did not slow down production excessively. Figure 35 - Port and Stbd Engine Room Work Areas (Shaded in Pink) Figure 36 - Typical Existing Conditions Reconstruction of the Battleship TEXAS 17

18 Figure 37 - Existing Structure Illustration Figure 40 - Keel or Longitudinal Section Welded at Top and Bolted as Shown Figure 38 - Notch Cut for New Keel or Longitudinal Section Figure 41 - Frame Plating Installed Figure 39 - Installation of Keel or Longitudinal Section Figure 42 - Frame Connection Brackets, Bolts, and Lightening Holes Reconstruction of the Battleship TEXAS 18

19 Figure 43 - Keel Support Bracket Repair Figure 46 - Aft Trim Tank (D-12) Existing Conditions Figure 44 - Frames Post Repair Figure 47 - D-12 Typical Frame Simplified Structure Figure 45 - New Tank Top Installed AFT TRIM TANK WORK The Aft Trim Tank, Space D-12, was also worked. This space was considerably smaller than the engine rooms, but the framing was in far worse condition. Over 10 tons of rust was removed from the space from deteriorated framing before work could commence. The repair method was similar to that conducted in the engine rooms. Figure 48 - New Frame Plating Fit to Existing Frame Reconstruction of the Battleship TEXAS 19

20 Figure 49 - Frame Bolting Figure 52 - New Keel Connections and Bolting Figure 50 - New Frame Flange Welded to Existing Frame Flange and New Frame Plating Figure 53 - D-12, Post Repairs (Note New Centerline Stanchions and Forward Bulkhead) Figure 51 - New Keel Section Installation Figure 54 - D-12, Post Repair, Looking Aft. Existing Framing and New Aft Bulkhead Visible Reconstruction of the Battleship TEXAS 20

21 Following all repair work, all removed piping, deck plate framing, deck plates, and interferences were reinstalled. Of note, all of the engine room piping was rigged out of the ship, steam cleaned, coated, and reinstalled. This resulted in a much cleaner engine room than pre-contract, which will ease future restoration efforts greatly. This project was an innovative approach to the repair of a vessel in very poor condition from within the watertight hull. TMC also conducted a repair on a ship from outside the hull using an innovative moveable cofferdam and cofferdam handling system. (Jacobs, 2013) The forward, starboard bow plating was severely damage from galvanic corrosion approximately 5 to 10 feet under the wind and waterline. A section of hull plating 10 feet in height by 132 feet long was replaced, underwater. A 30-foot long, 15-foot deep moveable cofferdam was used to accomplish this. Figure 55 - Battleship NORTH CAROLINA Hull Repair Project Periodic inspection and maintenance is far cheaper than mobilizing a contractor to repair damage after the fact. In the TEXAS Project, the repairs were completed inside of the ship and reinforced the same lessons learned. Both the owner of the Battleship NORTH CAROLINA and Battleship TEXAS inherited very old hulls and have maintained them afloat and safe for visitors with extremely limited resources. Battleship TEXAS is over 100 years old and is maintained afloat by a Texas Parks and Wildlife Crew of about 10 men and woman, compared to over 950 men when she first entered service. (Ferguson, 2007) Battleship NORTH CAROLINA is over 75 years old. Fortunately, both of these owners were and continue to be very proactive in improving the condition of their ships. Other museum ship owners should carefully examine these two repairs and ensure that their cathodic protection systems are in place and functioning properly. The scope of work for the Battleship TEXAS Project was to restore the strength of the keel, longitudinals, and framing in her engine rooms and after trim tank in preparation for dry-docking. The author has searched numerous resources, and cannot cite another repair of this magnitude that has been successfully attempted while the vessel remained afloat. The project was successful because of a proactive ship owner, thorough risk management, risk mitigation, and engineering by Taylor Marine Construction, Inc, and by very thorough and complex engineering analysis and practical design by Waller Marine, Inc. The completion of this project was the first major step in the recovery of the Battleship TEXAS, enabling her to be dry-docked, right now. The next step is a big one build a dry-berth for the ship, or develop some other concept of long-term repair to keep this National Asset and completely unique historic time capsule around for another 100 years. Figure 56 - Moveable Cofferdam The two most significant lessons learned from the Battleship NORTH CAROLINA Project were that external hull repairs can be conducted in place without dry-docking if the repair area is accessible with a cofferdam. Secondly, and more importantly, galvanic corrosion and its prevention should be heavily emphasized for all ship owners and operators. Reconstruction of the Battleship TEXAS 21

22 REFERENCES ABS. (2014). Guide for the Allowable Stresses for Localized Highly Stressed Areas. Rules for Building and Classing Mobile Offshore Drilling Units, Part 3, Chapter 2, Appendix 3. Baker, E. I. (1943). Introduction to Steel Shipbuilding. New York: McGraw-Hill Book Company. Carnegie Steel Company. (1903). Pocket Companion containing Useful Information and Tables appertaining to the use of Steel. Pittsburg, PA. Ferguson, J. C. (2007). Historic Battleship TEXAS. Abilene, TX: State House Press. Holms, A. C. (1908). Practical Shipbuilding - A Treatise on the Structural Design and Building of Modern Steel Vessels, Vol. I. London: Longmans, Green and Co. Jacobs, G. (2013, May/June -). Carolinas AGC Bestows 2012 Pinnacle Awards to Four High-Profile Projects and Industry Supporter. (M. Buckshon, Ed.) North Carolina Construction News, 8(2), pp Battleship Texas (BB 35) in 2014 The centennial year of her commissioning as a U.S. Naval Warship Reconstruction of the Battleship TEXAS 22