Fitting vacuum exhauster to industrial locos.

I've had a bit of a search around but havent spotted anything so apologies if this had been done before.

A few of likeminded nutters are looking to club together and acquire an old industrial shunter. However it was never fitted with vac brakes and as a result could never be used in passenger hauling. This doesnt really bother us too much but it would seem prudent to make it as useful as possible.

So the question is this, has anyone, or does anyone know of any shunters that have had an aftermarket vac system built/cobbled together for this purpose? And if so, how??

Cheers!

 

Is it essential to go for vacuum? Or is that the only brake your rolling stock is fitted with? Just that it's almost certainly easier to find a compressor you can drive from the engine than an exhauster,

 

Vac braked stock is pretty much all we have.

 

Use a compressor body as a vacuum pump. Put a large enough vacuum reservoir on board and a vacuum retaining valve. Then follow a basic diagram, 2" vac pipe through the loco with a dmu type brake valve.... Simple.

 

Done it plenty of times - if you want to PM me I'm happy to talk you through it, or you can come up and I'll show you how I've fitted some of mine.

Regards

Andrew

 

An exhauster off an 08 might be a better bet

 

If you can get one. 08 exhausters are also a bit bulky. As has been said above, using a compressor as an exhauster is just as easy as fitting an exhauster off an 08. The critical thing is whether there are spare belt pulleys on the engine that you can utilise or possibly double up on another drive. If you also want to rig it up so that the va also applies the loco air brake you have to find a vac/air proportional valve and they are getting to be quite scarce. So are DMU application valves but a decent ball valve can be utilised. After all, all it is doing is letting air into the train pipe.

 

The problem to using a compressor is a compressor is they generally are set to deliver a small quantity of air at higher pressure. There are some out there that can be converted (Broom and Wade being one) but the volume is lower than an 08 exhauster, and you may have to make other modifications to make it work reliably. To give a comparison - an 08 exhauster has the capability to move 75 cubic feet a minute of air to a pressure of 21" of Hg.... most readily available compressors are only upto 30-40cfm but do so at up to 150psi.

Depending how many carriages you are wanting to draw a vacuum on, would decide the size of exhauster needed - 2-3 carriages you could possibly use a DMU exhauster (which are smaller) - anything over 3 carriages and you'd want an 08 exhauster, or one off a 37 etc.

As for vac/air proportional braking - the question is really what each railway's SMS states, or requires for its operations. My own view is you should have proportional braking back onto the loco so in the event of an emergency you get a brake application, but those valves are getting scarce - I have been pondering manufacturing new but not sure if there is sufficent need to justify the costs involved.

 

Ah cracking responses chaps, its given a fair bit of food for thought

Next step is going to look at said engine!

 

Three notes regarding using DMU exhausters on locos: 1. As already mentioned they are getting pretty scarce now as there is more than enough demand within the DMU world to soak up any that become available. 2. They are only really designed to provide vacuum for 1 coach (each power car on a DMU has two and each car would only provide vacuum for itself and a maximum of 1 trailer) 3. They are likely to prove "sluggish" in a loco single pipe system as they are designed to slowly charge a "high side" resevoir as opposed to an 08 exhauster which blasts off the brakes on demand. All in all, better to use loco tech rather than railcar if you can...

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Using a reciprocating compressor as an exhauster is no problem and I can't think of any mods that would be needed. Middleton has two diesel locos using Westinghouse 25 cfm compressors and three with DMU exhausters, all of which work fine within the limits of our operations. The big problem with all engine driven exhausters is that you are generally wanting to create vacuum to take the brake off when the engine is at idling speed.
We would certainly be interested in a few vac/direct air proportional valves until we hear the cost!

 

We are busy adding a vacuum system to a 1951 class 11. Really interested in how you did yours. Piping and exhauster are in place but struggling to source a proportional valve??
Cheers, John