In-Track Repair of Concrete Ties. Deland Humpherys, Director Track Mtce

Transcription

1 In-Track Repair of Concrete Ties Deland Humpherys, Director Track Mtce

2 Concrete tie repairs: Shoulder repair process Normally the result of a derailment Lag removal and replacement process Broken lags through switches and turnouts Pad replacement and repair of rail seat area Worn pads result in rail seat abrasion

3 Lag Replacement Process Concrete switch lag gangs require the following equipment: Arc welder (portable) 6013 #8 weld rods (suggest 2 rods per lag) Electric generator (static) Air compressor (portable) Gas impact w/ socket to remove and install switch lags Electric drill w/ 6-9 inch extension and ¾ in. braided cup stone wire brush Chop saw or equivalent (used for cutting pieces of pipe) Hand tools (track jack, maul, screw drivers, clip removers, etc.) Welder s fan Replacement nylon sleeves

4 Lag Replacement Procedure Preparation Phase Use chop saw or equivalent to cut ½ inch diameter pipe into varied lengths ranging from2 to 4 inches (maintain an inventory of pieces of pipe). Walk concrete switch to identify missing or broken lags that require repair. For each broken lag that is identified, remove the other three lag bolts holding the same switch plate using an impact. Install track jack on one side of the concrete tie being repaired. Raise track jack to a height sufficient to remove both the switch plate and rubber pad.

5 Lag Replacement Procedure Preparation Phase (cont.) Using an electric drill w/ cup stone wire brush bit, clean the surface of each broken lag. This is the most critical step in the entire procedure. A clean surface will result in a quality weld. Operating electric drill with wire brush to clean lag bolt hole. Picture of a clean lag on left. Top surface of the broken lag should be silver after cleaning. Electric drill w/ wire brush drill bit.

6 Lag Replacement Procedure Installation Phase Select a piece of pipe that, when placed on the top surface of the broken lag, protrudes 2 inches above the tie. Using a hammer, strike the top of the pipe to ensure the pipe is against the top surface of the lag bolt. Prepare the arc welder for use by securing the ground and adjusting the output to amps. Place the tip of the weld rod inside the pipe.

7 Lag Replacement Procedure Installation Phase (cont) Beginning in the center of the lag, form a base of molten material in the bottom of the pipe. Articulate the welding rod in a circular pattern around the inner diameter of the pipe until a solid weld has been formed between the internal surface of the pipe and broken surface of the lag. Allow the weld to cool for 5-10 minutes. Install the Snap-On extractor, channel locks or pliers near the bottom of the visible section of pipe and rotate to remove the lag.

8 Lag Replacement Procedure Installation Phase (cont) If the weld breaks, repeat the cleaning process and welding procedure. Once the damaged lag has been removed, clean out the hole using an air compressor. Replace the nylon sleeve using a re-threading tool. After re-threading, a new sleeve can be installed. Reinstall the switch plate, pad, new lag bolt and other required track components.

9 Concrete Shoulder Repair If the shoulder fails for one reason or another, it is possible to core out the old shoulder and replace it with a new shoulder.

10 Shoulder damaged by derailment The first challenge is to identify the ties that can be cored and, therefore, repaired.

11 Shoulder damaged by derailment A concrete tie can be repaired if the shoulder is broken off cleanly but the structural integrity of the rest of tie is not compromised.

12 Shoulder damaged by derailment Tie is damaged beyond repair and must be replaced.

13 Shoulder damaged by derailment Horizontal split tie should not be cored.

14 Shoulder repair The first step in shoulder repair is to install gauge rods to maintain gauge. If standard gauge is not maintained, the shoulders will not seat properly. Recommend gauge rods every 6-8 ties.

15 Shoulder repair Depending on the severity of track damage, the application of gauge rods will also allow us to run trains over the track at a restricted speed while repairs are being made.

16 Grinding shoulders The remains of the old shoulder should be ground flush with the tie to prevent the drill bits from binding. Care must be taken not to nick the rail.

17 Double headed concrete drill Use only equipment designed for this purpose. A double-headed drill or a single head drill is positioned over the old shoulder.

18 Drill set-up Drill holes at a 6 angle. Use template for proper angle & settings. Outside lip of shoulder should be at the center of the drill bit. Drill 3½ inches deep, using plenty of water. Water should be flowing freely. Keep water and bit running at full speed while removing from hole. Hydraulics should be set at RPM.

19 Drilling Water is an essential part of the coring process and a large supply should be kept on hand. Don t drill with a dry bit.

20 Removing core If drilled correctly, the cores will be easy to remove. Cores should be checked to ensure proper alignment. Do not drill into the re-bar.

21 Shoulder repair Any water that is left in the hole should be removed and the hole should be clean and dry before resetting the new shoulder.

22 Mixing the grout Mix small amounts of grout at a time. The grout should pour easily into the hole. Don t hurry the process.

23 Set shoulders in correctly Use the proper replacement shoulder. Set the new shoulder. Clean excess grout from around the new shoulder. Grout should not interfere with insulator installation. For proper drying time, check manufacturer s directions. When dry, re-clip.

24 Pad Replacement Pads wear from: Environmental exposure Heavy tonnage Rail movement

25 Pad Replacement Process Remove rail, fasteners and pad Epoxy rail seat to repair and prevent abrasion Replace pad Replace insulators

26 Rail Seat Abrasion Epoxy is applied to the rail seat to repair abrasion damage and to prevent future abrasion. Epoxy is brushed on - easy to apply.

27 Out of Face Pad Replacement Use RCO, speed swing or crane to remove rail. For smaller jobs, rail lifters may be used.

28 QUESTIONS?