David C. Crammer 12640 Cowley Downey, Ca. 90242 (310) 861-8682 The following article appeared in the Sept/October 1994 issue of Rail Classics Volume 23 no. 5. The westbound double stack lead by B40-8 #8067 climbs Beaumont Hill headed towards Los Angeles and the Long Beach ICTF Yard. Suddenly a bell goes off in the cab, a red light just below the throttle flashes and the engineer experiences a noticeable drop in the RPM on his gauge. The red warning light has signaled a ground relay on a traction motor for one of his units. As a through train with only two men in the cab the conductor walks back along the units to find out which one has experienced the problem and upon entering the 3rd unit back, an GP60, finds the engine is idling rather than at "Run-8", a bell is ringing in the cab, and its red light signaling a ground relay is lit. Silencing the alarm on the control stand he starts the process to locate the problem axle. In a Southern Pacific GP60 the isolation switch to disconnect the traction motor is on the bottom right of the panel on the rear of the cab. He sets the switch to isolate since axles can not be isolated with the switch set in "RUN" and cuts out traction motor #1 by pushing in the dial on the top of the panel and turning it to the bottom left (clockwise the dial reads from the top "motors all in", "#3 out", "#4 out", "#1 out", and on the upper left "#2 out"). Returning the selector switch to "operate" when he pushes it to the run position the unit still remains in idle and the alarm bell and light signal that there is still a problem. Again silencing the alarm he returns #1 to service and isolates #2. When he returns the switch to run the unit again begins to load transmitting electricity to the axles that are still functional. With this he knows the problem occurred in traction motor #2. Had the ground relay occurred in the lead unit, a GE, the cutoff switches would still have been on the rear panel but work slightly differently with switches that are pulled out and then down after turning the dial to isolate. In a six axle unit such as an SD40T-2 the axles are isolated in pairs with axles numbered 1 to 6 from front to rear and isolated at 1-6, 2-5, and 3-4. When the first diesels were put into service the need to isolate individual traction motors was not anticipated. When Northern Pacific received its FT's in 1944 and 45 they would lose the power of the entire unit with a traction motor failure. When a four unit set suddenly was reduced to three on a 1% grade the loss of 1,350 HP could make the difference in the train being able to continue. Contacting EMD they asked if some way could be installed so that the unit could continue running with the other axles. EMD technicians arrived and figured out how to install the necessary switches in the units already on property. By the time Northern Pacific received their first F-3's in 1946 individual isolation switches were a standard feature. What has happened to cause this event? The main body of a locomotive simply serves as a massive electrical generator. The electricity it produces travels by cable to what is called the traction motor. The traction motor is the sturdy insulated metal frame along with the armature and the commutator which turns in reaction to the electrical field supplied by the armature. Should a cable be loose, moisture seep into the housing, or some other event cause a short the electrical connection is circumvented and until the problem is corrected the prime mover (diesel engine) will be unable to supply electrical energy to the armature turning the commutator which turns the pinion gear which reacts with the gear on the axle turning the wheels. The engineer or conductor reports over the radio to the dispatcher a "We have 306 event with unit #_____" and states that it is in a partially failed status. The dispatcher then logs this against the unit on the system wide computer. The information will sit against the unit until the problem has been corrected at a diesel service facility equipped to handle traction motors. Coming in over Beaumont the unit could be pulled off at Colton for diagnostic tests but since this is a hotshot train it will continue on to Long Beach and diesel service at Dolores Yard. At Dolores the first step would be to cut in the traction motor and load test possibly running the unit up and down the track if no initial problem was noted. If it did cut out again an electrician such as Phillip Anderson would check the traction motor first with a visual inspection of the cables with an obvious problem if one had become loose causing arching with the result that it had burned free and was hanging loose. If initial visual inspection had failed to turn up a problem the case covers would be removed to check for "bird nesting" where the wires became a tangled burned mess and a prominent smell of burned insulation. The commutator would also be checked to see if an armature brush had broken loose resulting in scorching of the commutator. Occasionally the "bird nest" would result in a locked pinion gear out on the road which means that a truck has to be sent out with a torch to burn off three of the pinion gear teeth so that the "bull" gear on the wheel can turn freely allowing the unit to be moved to the shop. If one of these problems are detected or if the unit continues to fail to load and no solution is discovered the unit is then be routed over to Taylor Yard in Los Angeles to have the problem corrected. First stop at Taylor will of course be the wash racks so that the personnel making the tests will not have to fight their way through road grime. Once the unit has been logged in the diesel service foreman makes note of the event listing the unit in a partially failed status that appears on the computer screen and printout. The computer prints it as a, "partial fail at 1800 03/19 acct 306" and on then next line "B/O REASON: ground relay". Diesel service can also check the history of the unit on the computer to see if it has had any recent traction motor work or if it has a history of traction motor problems under the heading "MEMO TEXT". Also on the "MEMO TEXT" the dispatcher can place the milepost location where the failure occurred. This is important since a traction motor may be effected by stress such as a change in angle of travel as in climbing a hill, dips, curves, etc. where the change causes a wire to make contact that may then fall back making it difficult to pinpoint the cause. The more information that is available to diesel service the better the easier it is to pinpoint the problem. The pulse tapes can also come into play showing the conditions the unit was operating under when the failure, which is reflected as a sudden flat line under the heading amperage, can be traced. In the first order of GP60's the older 8-track tapes are still in use while the rest of the order require the use of a lap top computer to download the information. The diagnosis may even require an electrician riding in a unit waiting for it to fail and then noting the conditions. Diesel service at Taylor does have on hand a meggar tester but since this requires disconnecting the necessary cables the unit may simply be forwarded on to the shops east of the racks after the routine maintenance has been performed and the motors checked for any visually obvious signs of failure. At the shops, besides the meggar testing, more elaborate testing can be performed such as "HIPOT" where a high electrical voltage test can be administered to the roped off locomotive to see if the unit fails. The traction motor can also be removed and then with easy access to the cables the meggar tester applied to the pairs of cables "A to AA" (armature) and "F to FF" (Field) the hand crank on the tester turned and if the reading stays at zero a short is present. If the meggar records a short or if repairs cannot be made at Taylor which handles brush changes, teflon bands, lubrication wicks and other minor items it heads north to Sacramento. A traction motor without the wheels weighs in at 5,200 lbs and with the wheels the weight is doubled. These heavy items can be shifted around the shop by crane with 6 overhead 15-ton, 1-100 ton and 2-30 ton (one 30-ton over the west drop pit). What is involved in changing a traction motor? The unit is positioned over the drop pit which has removable rail sections that can be dropped with the traction motor held in place. With the bolts holding the motor in place and the rail dropped an electrician can then undo the electrical connections connecting the unit to the traction motor. The whole assembly is dropped from under the unit and then moved sideways to be lifted again on the screw powered lift and then the 15-ton crane removes it from the rail and places it on blocks so that further diagnostic tests can be performed. A new traction motor is then placed on the lift and the operation is repeated in reverse. The center of the wheel on the new assembly is aligned with the mark on the rail and chocs placed under it to keep it from rolling out of place during the transfer. Using the screw lift again the operators lower it into the pit and them move it sideways in place under the unit so that the track it is resting on will match the track the unit is sitting on. As the lift raises it into place everything is eyeballed and WD40 sprayed on the pins to make sure everything goes into place smoothly (one man on each side of the unit). As it goes into the mount the chocs are removed and the lower panel bolted on to the truck frame. The shock then mounted on the frame and bolted on with an impact wrench. The lift is then lowered slightly to provide room under the unit for the electrician to attach the wiring. Once everything is in place and connected the unit is ready to leave with a new traction motor. The traction motor that has been removed is tested to see if the repairs can be handled locally. If it needs additional work beyond the capability of Taylor it is marked with a circled X and sent north on the back of a flatbed truck equipped with rails specifically designed for transporting traction motors to join traction others from all over the SP system in Sacramento. Almost the last vestige of the huge Sacramento shop system once maintained by Southern Pacific the wheel shops and signal shop are all that remain. Located in the yard next to the California State Railroad Museum they sit near the Sacramento River. Every traction motor over 6 years old must come in here for a rebuild as well as those where the motor has failed. If the motor is less than 6 months old they might just change out the failed component but over 6 months old and a traction motor brought in here will be rebuilt. The tear down shop operates one shift a day with four people and the traction motor shop is home to 72 crafts people working a 5 day week (Monday through Friday) over two 8 hour shifts. 2/3rds of these people man the day shift and the other third nights. In what takes four days to execute the whole process there will be a complete tear down and rebuilding of each traction motor that passes through the facility. The job is divided between three separate buildings with the first stage, the disassembly, handled by one man and his cranes in the truck shop. Here the wheels are separated from the traction motor to be sent over to the wheel shop. The traction motor goes by fork lift to the traction motor shop where the armature is pulled and frame and armature are worked on by separate teams. These will be reassembled and returned to work in what is a three man effort to install new wheels back in the truck shop. The wheels, that were removed, have been sent to the wheel shop to be refurbished and then either returned to be fitted to a rebuilt traction motor or shipped elsewhere on the system. As stated previously a traction motor with wheels weighs in at 10,400 lbs which is why 25 ton and 50 ton heavy duty suspended electrical cranes are a necessity for the tear down operation. Under the supervision of Frank Wooten four of these will have their wheels pulled in an eight hour day. Others that have already been stripped out at the point of origin to salvage the wheels will also be going through the system which is why 6 traction motors with wheels will be reassembled for every four torn down. The traction motor is taken over to the traction motor shop to be washed before its real tear down begins. First in an outdoor cubicle the loose grime is hosed off under pressure and then the real action begins. Sliding along on metal rollers with turnouts at various stages the first step is to press out the armature. As the dismount press pushes out the armature a saddle moves out under the armature to catch it and then pulls back to deposit it on the rollers . The frame, now separated from the armature, is then pushed down to its next stage where further disassembling takes place while the armature continues on a separate journey. Next stop for the frame is the large PROCECO washer where a 3-ton crane hoists it onto the platform which will hold it and any loose components during the 30 minute cycle. The wash cycle complete it will join two other frames for a four hour vacuum drying cycle in the domed PROCECO dryer . Drying complete it is checked to make sure all tolerances are within limits on the support bearing cap, commutator end bore, and pinion end housing and any cracks or defects repaired. This comes under the jurisdiction of a machinist/welder such as Pat Mannerino who literally goes over the frame with a fine toothed comb and who takes down the high spots and builds up the low ones repairing anything that has been marked with white chalk and tapping out holes. The frame is then set aside till the real rebuilding process starts. In its next stage high voltage electrical testing know as "HIPOT" (High Potential Voltage Test) is used on the frame to check for grounds and a PJ machine used to test it for internal grounds. Any components that need to be are replaced or re taped with insulation and the frame prepared to make it ready for the installation of the armature. These come out of the bins and boxes with nuts, bolts, and washers of different sizes. Bins with labels that read: "Black Clamps 11-027778" "Grey Clamps 11-048881" "5/16 Plain Washer 1/4" 26-288472" And other strange identifications dear to the heart of SP's Materials Management Dept. Meanwhile, the armature that was pressed out before the frame washing stage has been taking its own tour of the shop by a different route but starting in its own PROCECO washer and dryer finishing out a heated convection oven for a nine hour drying cycle. The armature then undergoes a Meggar test with 1000 volts to check for grounds and should the coil fail it is sent out to be rebuilt. New armatures come from Motor Coils Manufacturing in Braddock, Pennsylvania. Motor Coils is part of Morrison-Knudsen and is the primary supplier of traction motors and related components to every U.S. railroad. Morrison-Knudsen, which has been supplying railroads since 1915, added Motor Coils under its corporate umbrella in 1991. Under a unit exchange program (UTEX) Motor Coils provides a remanufactured traction motor in exchange for a failed motor returned by a customer as well as supplying rebuilt armatures. Armature coil wire is manufactured from round copper rod which is drawn and rolled to shape, coated and insulation-wrapped on an automated processing line. Field and interpole coils are manufactured with all new turn and ground wall insulation and everything electrically tested under pressure. Motor coils' production method for armature core-iron laminations ensures reduced temperatures which translates to longer insulation life and improved fuel efficiency. If the armature passes the Meggar test it is put in a vacuum impregnator and impregnated with varnish before going back into the oven for another nine hours. After being put on a rack it is given the HIPOT test again and then a machinist turns the commutator to clean it. Following this it goes to the electrical qualifying area, is checked for shorts, given another coat of varnish, under cut, epoxy poured on to seal it, spread with a stick, and then it is rotated to keep the epoxy from running. Once it has completed this rite of passage it must be balanced on both the armature and commutator ends using an IRD Mechanalysis which uses computers to determine how much weight to add for balance. After balancing the covers, housing, and bearings are put on so that it can be placed in the traction motor frame. The frame is tipped over on end and then the armature hoisted by a 2-ton crane is dropped in, a procedure carried out 8 times a day on the day shift and 2 times on the night shift. The armature now positioned in the frame and connected it is time to place the pinion gear which will interact with the gear on the wheel. This is heated by an induction heater while the armature is being load tested to make sure the bearings turn both ways and that nothing overheats. The gear is slid on and once the pinion gear cools everything is locked into place. While the frame and armature have been undergoing their rehabilitation the wheels that were removed have joined others that have come up singly from yards around the system. As with all other components their first stop is a good and thorough cleaning under high pressure using what is labeled as a #237 cleaner. The debris from the wheels and the keroscene like cleaner are held in a sump to prevent yard contamination. From the cleaner they are rolled down the track to the wheel shop building to be inspected, graded, and checked before proceeding to the next stage. The axles, wheels, and gears are separated with the help of an overhead 3-ton crane and a forklift. Gears are sent out to Mel's Cargo in Sacramento for regrinding. The axle will be checked for cracks on a Magnaflux machine, worked on the huge lathe and polished to a fine sheen (a 4 on the polish scale even though specifications only require a 7). Between 20 to 25% of the axles installed here are purchased new with the rest being turned on the centering lathe. Wheels that are mounted on them must be cut specific to the axle and again overhead cranes are necessity to lift everything into place. The axles are placed on horses and the wheels brought in and press fitted to the axle. When all bearings, caps, etc. are in place a protective coating from C&H Chemical #583 is painted on exposed surfaces to prevent rust. Assemblies that will be taken immediately to the truck shop are only coated on the outer ends while those that will be shipped out across the system have all exposed bare metal surfaces of the axle and gear are painted with the blue tacky coating. The traction motors with their armatures and pinion gears in place return to the truck shop and it is time to remate them with a wheel set. Using the cranes to maneuver everything in place the three men assigned to the reassemble job go to work to make sure it is ready to sit underneath a locomotive. Once the wheel set and traction motor become a single unit grease is applied to the gears in the form of 14 1lb bags of "Texaco TM Gear Lube- Heavy" which are dropped onto the gear as the traction motor is hooked up to cables and turned. The cover cases are bolted shut and a HUCK gun, heavy enough to require lift assistance from an overhead crane, which acts as a giant rivet gun to clip the bolt. The wheels are on, the armature checked out, and everything is greased up and ready to run. Traction motors reassembled at Sacramento may be shipped anywhere on the system equipped to install them such as Taylor, Burnham Shops in Denver, or Pine Bluff. Everything has now come full circle with our traction motor. From the time that our engineer first detected the problem and notified the dispatcher till everything was repaired and ready for duty under another unit. The crafts people at the shops and those who dealt with the problems on the road have speeded it on its way and have gotten the job done which is keeping the railroad provided with units ready to pull the load. I wish to thank Walt Costa, Frank Wooten, Clyde Thomas, Jack Hewing, Dwayne Bell, Fred Adams, Gary Comphel, Mike Antonelli, Pat Mannerino, Tony Rojo, Roger Robinson, Jesse Ramirez, Matt Hastings, Phillip Anderson, Brian Marty (of Motor Coils), Arthur B. Martinez, Wayne Huddleston, and Mike Furtney for helping me with this article