Western Railroad Discussion > Engine Coolant

I know this has been asked before but I’ll ask again. The reason locomotives don’t use antifreeze is because of??? Is it because pure water has a better heat transfer capability?

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good question.  ww might know............

66

Water presents a non-hazmat situation when it needs to be dumped, and also provides a easy way to just turn on any water spickt when it’s needed.

Rust inhibitor is typically added when a motor is at a shop.

Anti freeze is more expensive and presents disposal issues.

Some small railroads that have essentially “captive” motors may use anti-freeze, but they are the exception.

johnambrose Wrote:
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> I know this has been asked before but I’ll ask
> again. The reason locomotives don’t use
> antifreeze is because of??? Is it because pure
> water has a better heat transfer capability?

Yes. Pure water, with rust/corrosion inhibitors added, is far more efficient at cooling RR diesel engines that antifreeze mixtures. In fact, any and all EMD diesel engines were/are derated quite a bit if any antifreeze coolants are used in the cooling systems. Also, any sort of internal water leak on an EMD engine really isn't a big deal, as the modern lube oils will simply steam the water out. However, if there is antifreeze in the coolant, then you can pretty well kiss the main bearings good by.

https://www.trainorders.com/discussion/read.php?2,1339698
http://cs.trains.com/trn/f/741/t/95421.aspx

Basically what I read, any leak into crank will wipe out bearings.
System is not designed for coolant.
Cost.
Benefit is limited as engines are kept running or hooked up to aux power or have startup systems.

Bob

Burlington Junction at Rochelle, IL are hooked up to electric, (engine Block heaters like autos???).

I'd guess there is also a power interuption system for notification of power out or an auto start system??
It would be very costly to keep units running when they are only used sporatically but I do wonder with the extreme cold if they are left running.

Bob

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High capacity glycol-based systems tend to find every way possible to leak. Put straight water in there and no more leak. Always wondered if the molecules in glycol were smaller than water.

I've posted before that we used to build hydraulic systems for fire resistant applications using some variation
of Houghton 519 or 520 water glycol mix. They'd usually seal up hot but cold every threaded fitting weeped,
shaft seals leaked, the stuff was awful. It was mandated by the insurance carrier so that was that.

Out

Great answers here.  

I've noticed engines from CSX and NS use more water for coolant. Sometimes it's clear and other times there is a pink hue. 

Hookdragkick Wrote:
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> I've noticed engines from CSX and NS use more
> water for coolant.

Do you mean more than other railroad's locomotives?

Sometimes it's clear and other
> times there is a pink hue. 

The "pink hue" is the corrosion inhibitor additive. For what it's worth, it is definitely NOT recommended to ever use just raw water in ANY cooling system.

Coalca Wrote:
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> High capacity glycol-based systems tend to find
> every way possible to leak. Put straight water in
> there and no more leak. Always wondered if the
> molecules in glycol were smaller than water.

No.

Elizabeth

Hookdragkick Wrote:
-------------------------------------------------------
> I've noticed engines from CSX and NS use more
> water for coolant. Sometimes it's clear and other
> times there is a pink hue. 

The pink should be the anti-corrosion additive.

Coalca Wrote:
-------------------------------------------------------
> High capacity glycol-based systems tend to find
> every way possible to leak. Put straight water in
> there and no more leak. Always wondered if the
> molecules in glycol were smaller than water.

Not sure what the reason for this would be... glycol is a significantly larger molecule than water. Water is H2O (3 atoms), ethyleneglycol is 10 atoms... C2H6O2. Being an organic molecule, glycol may attack plastic/rubber seals if the wrong material is used...



Edited 1 time(s). Last edit at 01/30/19 11:07 by exhaustED.

In hydrauilic systems glycol based fluids were compatible with buna-n (nitrile, synthetic rubber) seals. The exotics
(Pydraul, Skydrol (used in aviation applications)) needed a further synthetic used as viton. Viton in early applications
was extremely expensive though when used in standard applications offered a much longer shelf life.

Out
 

Depending on the operating temperatures used in locomotives, a 50/50 mix of ethylene glycol and water has about 20% less heat transfer capacity than pure water. So, you would need some combination of higher flow rates and/or larger surface area to use antifreeze. Even if you could use antifreeze to keep the engine from freezing up in cold weather, the lube oil won't flow at low temperatures, meaning your chances of getting the engine spinning fast enough with the starter motor are slim.

Good answer, thanks.


Nudge

Just to add to this discussion, despite those antifreeze sponsors on the cars, race cars use pure water with additives too, for two reasons; 1) better heat transfer, 2) antifreeze is slippery when it gets spilled on the track.

robj Wrote:
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> Burlington Junction at Rochelle, IL are hooked up
> to electric, (engine Block heaters like
> autos???).
>
> I'd guess there is also a power interuption system
> for notification of power out or an auto start
> system??
> It would be very costly to keep units running when
> they are only used sporatically but I do wonder
> with the extreme cold if they are left running.

We have 480V block heaters on our two locomotives at our plant.  Unfortunately the batteries have failed, so we have them running tonight. 
>
> Bob

When I was an engineer for a northern shortline we had high voltage power cables we plugged in after shutting down the unit (s) during winter. The heaters kept the lube oil and coolant warm. However there were some Monday mornings after sub zero weekends when the cab of the SW 1500 was so cold we had to scape ice off the inside of the cab windows to see. We usually would go to a nearby resturant for a long breakfast or sit in the caboose/office with it's oil heater to keep us warm waiting for the the engine cab to warm up so we could go to work. Back then the railroad's owner specified this procedure...and even let us bill him for breakfast. 

Being retired...I don't miss winter on the railroad.

exprail