VACUUM INSTALLATION

1382 is an industrial shunter and fitted only with air braking. Now in heritage we felt is would be useful to add vacuum braking to operate with Mk1 coaches and other vacuum fitted rolling stock.
We purchased 1382 with vacuum fitting already started. The vacuum through pipe had been installed by Briddons with a tee off into the engine bay. It also came with a Northey exhauster and an AV2 proportional valve but no documentation nor any plans how to complete the installation.

Information for the Northey exhauster was elusive although I am grateful to Eddie Gallashan of Bo’ness & Kinneil Railway for providing technical manuals that helped identify the Northey exhauster a type 90RE.
It was clear that installing the Northey exhauster was not going to be easy. It came with no manifolds. The drawings also identified that the drive to the exhauster would have to be via a lay shaft, a simple drive belt and pulley was out of the question:

Having no experience of such heavier engineering (my background being an electronics engineer) installation of a lay shaft was somewhat outside of my skills area and combined with the tight space in the engine bay it was decided to find an alternative and simpler solution.

At this time (2024) 1382 was resident at Quainton and it soon became clear the knowledge / help for designing and fitting of vacuum braking was not available.
Help did however come with the offer to look through and use the onsite spares for Quainton’s class 115 DMU which was slowly decaying in the yard.
Searches identified a spare Clayton Dewandre exhauster with oil separator along with the automatic feed and isolating valves. Further searching on the internet a driver’s brake valve was found and purchased so I now had the main parts for a DMU style vacuum system:

The basic design for the vacuum brake system is based closely on that for 1st generation railcars. The Railcar website contained most of the information needed to put together the design for 1382. Over the next few months the various parts needed were purchased. The mounting frame for the exhauster was fabricated and also the drivers brake handle assemblies. The left hand drivers brake handle has a crank in it to overcome a clash with the air brake handle. This was preferred to altering the drivers air brake handle positions and moving the associated pipes and valves. Simply put if it ain’t broke, don’t fix it! Here are the left and right hand vacuum brake handles and shafts – why the gearing? Two reasons, one to reverse the brake handle rotation so it was the same as the air brake handle and second to drive a rack to connect the two brake handles together. Using a simple crank wasn’t going to be easy due to limited space under the cab console:

The current installation has only the left hand vacuum drivers brake handle fitted and successfully tested.

Below: Fit and dimension check for pipe and valve assembly prior to installation:

Below: Piping and automatic brake valve installed in disused left side battery box. The tee off point is for future installation of a high vacuum (28″) cylinder and isolating valve (same as DMU design). Note train pipe vacuum is as normal ie 20″ – the purpose of the high vacuum cylinder is to speed up brake release.

Below: left hand drivers brake valve installed with brake handle drive shaft – note this identified the foul with the air brake crank and resulted in the vacuum brake shaft modification.

Below: the final run from the vacuum brake valve, through the filter unit (note the check valve inside this was removed as this run has to be bi-directional) and via an isolating cock to the train pipe connection.
Note also the drive pulley from the generator to the exhauster – belts yet to be fitted.

And finally the cab console with left hand vacuum drivers brake handle (next to first aid box) and duplex vacuum gauge fitted (below the greenstart button).