Hey everyone, I was wondering what keeps water from running into the prime mover of the locomotive. The exhaust shows no rain caps (Like we put on tractors, and semi’s as well as genset’s.) I am in tractor troubleshooting and I know my way around engines, and we all know…water or any moisture inside a engine doesn’t work, expecially on diesels. Thanks Mike
Hi Mike,
I have been a truck driver for more than 20 years, and stack flappers, while there are some still out there, are not all that common anymore, at least here on the West Coast. The exhaust system on a truck Tractor has it’s low point below the cab, then rises back up quite a bit to the turbo charger, that dip would keep anything less than several gallons of water from entering the engine. Here in Portland, OR we get quite a bit of rain, but the area of an exhaust stack’s opening is relatively small, and doesn’t collect that much water. I have gone on vacation and had a tractor sit for 2 weeks in rain and start without trouble. The hot exhaust gases will evaporate what little does accumulate in the small amount of time a tractor is typically shut down. Long term storage (many months to years) exposed to the weather would warrant capping a stack, but generally not a tractor that sees regular use.
I don’t know if a locomotive’s exhaust system has a similar low point, but I would suspect it would, at least partly for this reason. Also locomotives have traditionally been idled extensively in the past, and the exhaust would keep any water from entering the stack. I would imagine that a locomotive stored long term would also warrant capping a stack too.
Doug
Mike
On the bigger diesels muffler there is a drain tube that drains water from the muffler. On our Komatsu and Cat equipment it drains next to the engine blowby pipes. Just a couple weeks ago I had a John Deere 450CLC excavator that did not want to start. The Muffler filled with wet snow that got blown into it and froze solid. After heating it with a weed burner about enough water came out to fill a 2 gallon bucket.
Pete
Diesel locomotives in active service are rarely shut down, and while the diesel engine is running there’s no issue about rain collecting in the exhaust system. When locomotives are stored for any length of time, as many are now because of the economy, railroads do cover the stacks. – Andy
Thank you everyone, and thanks I did wonder why our old grain truck and tractors had caps (Most our exhausts run straight down into the manifold hence water runs right on in.) but not a lot of the newer semi’s I seen. There is a new pete down the road with 7" straight’s on it with no cap, I see now because I was thinking how it was possible because a drain at the bottom of the stack would totally defeat the purpose of the stacks. I now understand thanks! Mike
Well semi’s are easier to explain. Like was mentioned, the exhaust has to aim towards the road to get the stacks, and if you look somewhat carefully you notice usually a small J-shaped section of flexible steel tubing hooks up to the stacks, kinda like a toilet. Any water that would get in could get dumped out by unhooking the J-section. And as mentioned the heat of the exhaust would evaporate the water. A good example of this would be to shovel a little pile of snow right under the exhaust pipe of your car and then start it up to warm up. By the time you’re done shoveling your car out and the engines warmed up there won’t be any snow pile there. And I’m sorta suprised no one mentioned this, but unless it’s raining reeeaaall hard and the semi/train is just sitting there idling, the speed of the exhaust won’t let rain get in. You see it all the time in serious off roading and rock crawling, trucks going through mud puddles up to the doors. As long as the engine isn’t turned off, even a submerged tail pipe won’t let water in very easily. I can also atest to this in an incident in one of my old cars. I wasn’t really thinking about the air intake being mounted in the bumper practically and went through a rocker panel deep puddle. It’s fun trying to dry your engine out by running it when it barely wants to run. Heh, some of the crap I did in that car I’m suprised it lasted as long as it did. Heck engine even ran upside down! Ah, don’t ask [:I]