Number 164 Underwater stern tube seal replacement in Mississippi In-situ propeller blade seal replacement in Togo

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1 Number 164 Underwater stern tube seal replacement in Mississippi In-situ propeller blade seal replacement in Togo Insert repairs in Marseille and Togo prevent drydocking

2 Permanent rudder repairs now possible without drydocking Hydrex has developed an entirely new method enabling permanent repairs of rudders without drydocking the ship. Permanent repairs were hitherto not possible and ships had to drydock in case a major defect was found. The newly designed equipment is lightweight and can be mobilized very rapidly in our special flight containers. Therefore this new service is now available worldwide. Major defects on rudders very often cause unscheduled drydocking of ships. The new method designed by our technical department allows engineers, welders and inspectors to perform their tasks in dry conditions. Class approved permanent repairs in-situ, without moving the ship, are now possible and commercial operations can continue. Steel repairs and replacements can be performed and pintle and bushing defects can be solved without the loss of time and money associated with drydocking. The equipment can be mobilized within hours to any port in the world. It is available for rapid mobilization from the Hydrex headquarters in Antwerp and at the offices in Tampa, Algeciras, Mumbai and Port Gentil. UNDERWATER TECHNOLOGY 2

3 Editorial Table of contents In this issue of our magazine we talk about a wide range of operations recently performed by Hydrex diver-technician teams. All jobs were performed while the vessels were berthed or at anchor, saving the owners the need to drydock. The first article deals with a stern tube seal replacement that was carried out in Gulfport, Mississippi on a general cargo vessel. During this operation divers from our offices in Tampa and Antwerp worked closely together to perform the necessary repairs with only the minimum of delay for the customer. In the next article you can read about a propeller blade seal renewal that was carried out on a RO-RO vessel in Port of Lome, Togo, by our office in Port Gentil. This office is fully operational and can mobilize immediately for any kind of operation whether large or small anywhere on the west coast of Africa. The magazine ends with an article on two insert jobs, one of which was also carried out in the Port of Lome, and the other in Marseille, France. Like all operations carried out by Hydrex, the repairs in this magazine were performed according to class approved procedures and the strictest safety regulations. Best regards Dry underwater stern tube seal repair inside flexible mobdock ISO 9001 certified To receive a free copy, fax to: Hydrex N.V or to hydrex@hydrex.be Underwater stern tube seal replacement in Mississippi 4-6 In-situ propeller blade seal replacement in Togo 8-9 Insert repairs in Marseille and Togo prevent drydocking Boud van Rompay KEEPING SHIPS IN BUSINESS 3

4 Underwater stern tube seal replacement in Mississippi Hydrex diver-technician performing welding work on the rope guard To stop oil from leaking from the stern tube seal assembly of a general cargo vessel, a Hydrex diver-technician team was mobilized to perform permanent repairs on the vessel during its scheduled stop in Gulfport in the state of Mississippi, U.S.A., last month. The team together with the diving equipment was mobilized from the Hydrex office in Tampa to set up a diving station at the berthing location. By the time all necessary preparations had been made, the team had been reinforced with additional technicians from the headquarters in Antwerp and was ready to assist the vessel as soon as it arrived at Gulfport. Hydrex diver-technician jumping into the water 4

5 Protection ring brought to the quay Damaged seal brought to the surface The operation started with a thorough underwater inspection of the stern tube seal assembly, followed by the removal of the rope guard. This revealed a protection ring which was removed to create more space for the renewal of the seals. Next the split ring was also disconnected and brought to the surface to be cleaned. A consequent inspection of the running surface of the stern tube seals showed that it was severely worn and no longer functional. After a discussion with all parties involved, it was decided to remove the spacer ring and create a new running area. The Hydrex flexible mobdock was then installed around the stern tube seal assembly and a dry underwater environment was created in which the diver-technicians could remove the damaged seals one by one and replace them with new ones. After these were bonded the entire assembly was put 5 Stern tube seal assembly during seal bonding

6 together again and weardown measurements were carried out with positive results. The flexible mobdock was then removed. Finally the protection ring and the rope guard were reinstalled, concluding the repair. During the first inspection of the stern tube seal assembly it had become evident that the propeller blades of the vessel were damaged. The leading edges of all four blades were therefore grinded by the Hydrex divers to bring the propeller s efficiency back to its optimal condition. The team worked in shifts to perform the stern tube seal repair within the shortest possible timeframe. By keeping his vessel out of drydock, a lot of time and money was saved for the customer. Hydrex diver-technician working inside the flexible mobdock Hydrex flexible mobdock installed around stern tube seal assembly Measuring the damage on the propeller blades 6

7 KEEPING SHIPS IN BUSINESS Fully equipped for a worldwide fast response 7

8 In-situ propeller blade seal replacement in Togo Pontoon next to trimmed propeller Oil was leaking from one of the blades of the propeller of a 210 metre RO-RO vessel and the vessel could not use its propeller anymore. Hydrex therefore mobilized a team to the ship s location in Port of Lome, Togo to perform emergency repairs. The operation was carried out while the vessel was at anchor and trimmed so that the affected blade seal surfaced. After all the necessary equipment had arrived on site together with a workboat and a pontoon, the repair started with the installation of chain blocks to enable the team to lift the blade from which the oil was leaking. Seven of the eight blade bolts were easily removed, but the last bolt was firmly stuck and could only be removed by cutting it with the aid of special equipment. Subsequently the propeller blade was lifted and the damaged propeller blade seal was replaced with a new one. After the new seal was bonded, the blade was repositioned and the remaining seven bolts were secured again. Finally a successful oil pressure test and an underwater inspection of the entire propeller were performed, concluding the repair. With the oil leak repaired the vessel could use its propeller again and was able to leave Port of Lome. Welding work prior to installation of lifting chains 8 Installation of new propeller blade seal

9 Hydrex office in Gabon The operation was carried out close to the Hydrex centre in West Africa. The office is located in Port Gentil right next to Cape Lopez Bay, which offers safe anchorage for all types of vessels (up to ULCC) on a sand/mud seabed with minimum depths of 50 metres. Thanks to the sheltered environment of the bay the swell is limited. This makes it the best location to carry out repair or maintenance work on a ship, barge or rig in ideal conditions. The central location on the African West coast makes Port Gentil the perfect place for a logistical and Repositioning of propeller blade efficient hull cleaning service to vessels in the region. There is a shortage of available drydocks in West Africa, so by carrying out repair and maintenance work insitu, Hydrex saves ship owners not only the trouble of having to find one but also the loss of time and money docking causes. Hydrex diver-technicians are also trained to perform propeller blade replacements underwater All maintenance and repair work will be carried out following the necessary safety measures and according to the class approved Hydrex procedures. By working closely together with the headquarters in Antwerp, this office benefits from the company s long tradition in the ship repair and offshore industry. equipment support base for the entire region, and allows the new Hydrex office to also mobilize to any other suitable location in West Africa in a very short timeframe, making both emergency and scheduled operations possible. As a consequence of the warm waters surrounding the African continent, there is an increased risk of fouling on vessels sailing in these regions. Like all Hydrex centres, the office in Port Gentil is equipped with several sets of the Hydrex patented underwater hull cleaning equipment. This enables Hydrex to offer a very fast and Fully operational Hydrex office in Port Gentil 9

10 Insert repairs in Marseille and Togo prevent drydocking Damage in flat bottom plate of general cargo vessel In April diver-technician teams carried out in-situ insert repairs in Marseille and Togo to help ship owners avoid going off-hire and keep their vessels in the water until the next scheduled drydocking. One of the repairs was performed on a general cargo vessel while it was berthed in Marseille. An inspection performed shortly after arrival at the location indicated that an insert of 800mm x 400mm was needed to repair the damage that had occurred on the flat bottom of the vessel. The actual operation started with the preparation of the insert and the installation of an external cofferdam over the affected area. Next a frame was cut away to enable our team to remove the damaged bottom plating Preparation of insert plate for repair on general cargo vessel 10

11 Tailor made cofferdam installed on flat bottom plate of barge Outboard side of new insert plate Crack in flat bottom plating of barge in Togo New insert repair after full penetration weld and to fit the new insert plate which was subsequently secured with full penetration welding. At around the same time Hydrex was contacted to carry out an insert repair in accordance with RINA on a barge in Port of Lome, Togo. During an inspection of the inside and outside of the affected area, two cracks were found in the flat bottom plating. A tailor-made cofferdam was then installed on the outboard side of the cracks, after which the affected areas were cut away and two inserts were installed, one measuring 300mm x 319mm and the other 500mm x 300mm. A full penetration weld was executed on both inserts from the inboard side in accordance with the Hydrex approved welding procedures. Finally the integrity of the insert repair was verified by ultrasonic testing. Both operations were carried out without delay for the owners who could sail their vessels again free of cracks and without the need to go to drydock. Framework reinstalled over new insert plate 11

12 Keeping ships in business Hydrex underwater technology and services provide high quality solutions to the repair and replacement problems encountered by ships and offshore vessels. We deliver a complete line of services that may reduce or avoid off-hire time entirely. From major projects to simple inspections, Hydrex has the worldwide facilities and capability to meet your demands. Drydocking is not necessary so time, trouble and expense are saved by doing work in-situ. Hydrex services cover highly technical major repairs or replacements of a ship s external underwater equipment such as thrusters, propellers, rudders, stern tube seals and damaged or corroded hulls. Hydrex Headquarters Antwerp Phone: (24/7) hydrex@hydrex.be Fax: Hydrex US - Tampa Phone: (24/7) info@hydrex.us Fax: Hydrex Spain Algeciras Phone: (24/7) info@hydrex.es Fax: Hydrex India - Mumbai Phone: (24/7) mumbai@hydrex.be Fax: Hydrex India - Vishakhapatnam Phone: (24/7) vishakhapatnam@hydrex.be Fax: Hydrex West Africa Port Gentil Phone: (24/7) westafrica@hydrex.be 12