Western Railroad Discussion > Diesel Locomotive radiators.

Something I haven't seen discussed and in which I am always interested is the subject of cooling diesel motors in locomotives.

The one diesel with which I'm most familiar is C&TS #19, the "Pineapple". It has two radiators, one on each end, two prime movers of course, so there is a separate radiator for each. Of course, with this locomotive, it has a lot in common with CAT products because of the CAT diesel engines for prime movers. As I recall, it took 8 gallons of anti-freeze per engine.

Now, I've heard it said that railroads don't often use Anti-freeze in radiators for several reasons, one being that prime movers often have internal leaks and anti-freeze could contribute to early engine failure in these motors. However, in the Pineapple, we used Anti-freeze, probably because of the high-altitude use and a greater chance of freezing up in even the summer. However, we often hear that crews have to drain water when a locomotive is left unattended and not running, a bad order for example.

One more item for this discussion is that diesel motors tend to run cooler than their gasoline counterparts. It could be that radiators don't need to be so large, however, consider the kind of heavy service in which they are used. I'll bet that diesels really get to high coolant temperatures in some places, example, Tennessee Pass or the Blue Mountains, especially.

So then, questions for the "real railroaders":

- Do most locomotives use only water and not anti-freeze? Consider that locomotives may use 50 gallons of coolant, that could be a significant amount of anti-freeze.

- Does anyone have any experiences to recount when a locomotive radiator boiled and the prime mover perhaps overheated, maybe even to the point of being damaged? The manufacturers probably built in safeguards against this damage, especially with the coming of electronics to this application.

Thanks,
Jim Burrill

tolland wrote:

> Consider that locomotives may use 50 gallons of coolant, that
> could be a significant amount of anti-freeze.
>

According to Del Grosso, BN's SD40-2s have about 240 gallons coolant and about 250 gallons lube oil.
Dash 9s have 380 gallons coolant and 410 gallons lube oil.
SD70MACs have 276 gallons coolant and 436 gallons lube oil.

New information from a contact at UPRR: The amount of coolant seems to vary with model, but it is typically in the hundreds of gallons, maybe 250 to 500 depending on locomotive type. Also, as to Anti-freeze, the only ones on UP to use Anti-freeze are SD90MAC's.

A diesel and a gas burner are a lot alike in that they are heat engines. Ethylene Glycol serves two purposes. One is to not freeze and the other is to allow the engine to operate at a higher temperature without excessive coolant pressure. The hotter you can safely operate an engine, the better is the fuel economy. Liquid cooling is a better cooling method than boiling. More stable and you can transfer more heat. Cat makes engines that are designed to boil but most of them are natural gas engines. So if you really want to squeeze the maximum amount of power out of an engine, run antifreeze. I suspect, but do not know, that a lot of the train lore is a cheapskate bottom line penny pincher that won't spend any money on maintaining an engine but would rather run it into the ground so his bottom line looks good.

On my most recent trip, we had the IMRL 8924 (trailing) and alarm bells started ringing. The bells indicated a "Hot Engine", the cause being the shutters failed to open. The temperature gauge read a wopping 230 degrees! I quickly found the shutter control switch and got the shutters open. The engine cooled down and we continued as normal. If an engine overheats, it will usually stop loading or load (Load = Develop power to pull the train)at a reduced rate. You arn't supposed to shut them down, as that definately won't let them cool down well.

Now, as for the rr's being cheap skates being the reason they don't use antifreeze, I don't buy that. At least all of the railroads that I've noticed (UP, BNSF, KCS, IMRL) put in tablets to help inhibit rust and those tablets are as much as antifreeze would be or more. However, one of the locomotives we have down on the Midland Railway in Baldwin City, KS had stop leak put into the radiators to help seal a leak caused by rust, so this shows it can go the other way, too, but as far as railroads go today, as I said before, the ones I've seen DO use rust inhibitor (We do).

imrl

Anti freeze is always mixed with water, usually 50/50. This lowers the freezing temp plus raises the boiling temp. If you run a pressure system the boiling temp is higher. If you do not run anti freeze you use an additive to prevent foaming and rust.

QUOTE:
"One is to not freeze and the other is to allow the engine to operate at a higher temperature without excessive coolant pressure."

Good points. Perhaps some of you operators can tell us landlocked people what temnperatures you see in actual operation. Gasoline engines commonly run at 225 F and we have done some work at 235 and even as high as 250 F but that takes propylene glycol and is hard on plastic header tanks.

The additives I saw added to engine cooling water was a dye so that when an oil sample is taken every 30 days at FRA mandated inspections, they check the oil sample for the dye put in the cooling water. Presence of the dye in the oil means a leak internally in the engine and means that maintenance is needed or they'll have bigger problems later. The dye can be lime green, pink, blue/purple, and doesn't mean the water is a hazardous material, it's just to show dye has been placed in the water. I heard UP used antifreeze in a few engines but water is the more common practice because manufactured engine blocks (most EMD) vs cast engine blocks (most GE) won't tolerate the antifreeze.

I was told by UP mechanical that we don't use antifreeze because if it leaks into the cylinders, it wont compress, and blow the head off or throw a rod.

Im not sure about whether Glycol will compress or not but water most certainly will not compress. The problem is that EMD and GE FDL series engines were not designed for Antifreeze in the cooling system, and it is not worthwhile to modify the design. All newly designed cleansheet of paper engines are likely to be able to use Antifreeze from now on.

With our 710G3B/G3EC 12 cyl EMD Engines,we use an additive that includes--- Water--Sodium nitrate--sodium tetraborate--sodium hydroxide, and sodium metasilicate. Basically a rust inhibitor/water stabilizer that turns the water shades of pink depending the concentration level.

One reason locomotives don't use antifreeze is they are assembled with
seals that are not compatible with ethlyene glycol! They would disentegrate
with contact of the antifreeze!

You can get seals that are compatible with antifreeze, but they can get expensive!

Most locomotives use straight water and use adtitives to fight corrosion and rust!

This is also the primary reason locomotives are left running 24/7, especially in the colder
regions!

Mike


 

SSW41 Wrote:
-------------------------------------------------------
> I was told by UP mechanical that we don't use
> antifreeze because if it leaks into the cylinders,
> it wont compress, and blow the head off or throw a
> rod.

As far as I'm aware all liquids are essentially incompressible - it's why hydraulics work, the icompressibility allows force to be transitted very effectively.

I worked for Santa Fe/BNSF for decades, and never worried about radiator fans, they were all automatic. Now retired, I'm hog- headed again, on the Midland Ry at Baldwin, KS. They bought two engines from Farmrail this summer, and they have manual fan switches. 8250, an old Paducah GP10 has 4 fan switches, and I try to keep it between 165 & 175 degrees. If theyre turned off, it will shut down without warning above 180 degrees. Also, in time for cold weather, they put about 200 gallons of antifreeze in each unit. In very short order, 4079, a former SP GP20 started leaking coolant out of both water pumps. They had to drain the coolant into barrels, and put on two new pumps. But, we dont have to drain them in cold weather now, and hopefully we will have no more coolant related failures.

Posted from Android

Apparently a thread that’s revived every four years :)

Modern GE’s report water and oil temps around 200 ish under sustained loads. At idle the temps are about the same.

I haven’t looked at the EMD screens (pain to navigate - and really don’t care) but imagine they run about the same.