Shop Notes - Waking Up A Monster
Article
by Claude Gaudet.
I would say that one of the toughest things with diesels is starting them up cold. Once they are started they can run for thousands of hours without a problem. However, one of my best experiences was on a Canadian National 2000-series locomotive in the early 1980s, probably an M630 but I'm not sure. The M630's were a product of Alco's Canadian subsidiary, Montreal Locomotive Works (MLW). This locomotive had a 16V 251 engine with an air starter.
From my experience I would say that they were pretty good horses. According to the CN classification system, they were listed as, "MR-30b." "M" for Montreal Locomotive Works (Alco or Bombardier), "R" for Road switcher, "30" for the hundreds of horsepower, "b" for batch (as in a "batch" order for the same model). The most popular peculiar thing about these locomotives was that they were the only ones equipped with air starters. Starting this engine was like a dynamite blast! As the starter button was just a few feet over the starter, only experienced mechanics were able to fire them without jumping down the running board! Everything else on these engines was pretty much standard equipment: V-16 251 type engine with diesel direct injection; turbocharger, aftercooled 3000 HP, PG electro-hydraulic engine governor, WABCO air-cooled two-stage air compressor, mechanically driven radiator cooling fan (90° angle drive), including Eddy current clutch, 26L scheduled air brake system, electrical fuel pump, and crankcase exhauster.
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| Photo courtesy Canadian Train Photographs by Pat & David Othen |
This particular locomotive that I was trying to start was in the shop for the past 10 months recovering from a major wreck. When the locomotive was finally ready they brought it into the Test Shed for us to start it up and perform all functional and load tests. The loco arrived in the Test Shed on the afternoon shift to be inspected and serviced with all kind of lubricants, water and fuel, and was ready to start at the beginning of the night shift. When it was ready, the night shift guys tried to start it up. The engine was turning enough, but there was no ignition at all. That locomotive was stopped for so long, all the piston rings were dried and stuck in the grooves, and the valves and guides were coated with old carbon deposits like chunks of rock! The night shift guys tried to induce ignition by filling the engine with hot water, but with no luck. Then they tried spraying ether ("starter fluid") into the air intake. During startup the engine was able to burn the ether, resulting in a lot of light gray smoke but nothing else.
So the engine sat until the next morning. When I arrived for duty in the morning, the foreman asked me to try to wake that baby up. He thought that I would find it to be a real exciting challenge, but in reality I just didn't know what to do. I did roughly the same thing as what the guys on the night shift did before and obtained the same results. During this time there was a construction company working just next door to us doing some underground work and they were using a motorized pump. Next to this pump I saw a 10 gallon drum of gasoline. I thought to myself, "I have enough compression to ignite ether but not enough for fuel... so let's go somewhere in the middle... a gasoline and diesel fuel mixture!"
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| Photo courtesy Canadian Train Photographs by Pat & David Othen |
So I drained the primary fuel filter canister and filled it with gasoline. I connected an extra locomotive on to the locomotive I was working on so I would have more air for the starter, and I tried to fire the sleeping giant again. After the first two or three turns I heard sounds that I never heard before, and from that moment I knew that I woke up the monster. Because of the gasoline, the engine wanted to explode at each cylinder injection, and the injection timing was some kind of disturbed, but something was happening. I had to hold the starter on for at least 30 seconds while the engine was roaring, screaming, and shaking itself like it was under torture! When I felt that the engine was able to turn by itself, I undid the starter. I had to continue pulling on the fuel lay shaft in order to force feed it with fuel. At this time the minimum speed I was able to get was about 400-450 RPM (maximum rated speed is approximately 1100 RPM). After one or two minutes I felt something falling on my head. It was carbon chunks from the size of a peach pit to small dust thrown out from the turbocharger and falling all around the locomotive. I looked up in the sky and saw a thick, black column of smoke up to twenty-five feet high and about twelve feet wide, like mushroom cloud from an atomic bomb! I looked down behind me and saw all the guys standing around with their jaws dropped, enthralled as if they were watching a fireworks display! For a young mechanic such as I was, it was certainly a dramatic event!
For more information on MLW's, see http://www.trainscan.com/cnlines/cycl/loco/mlw/