Looking for examples and knowledge about mounting air pumps horizontally on a locomotive. Has it been done before? Is there a special reason not to? Any maintenance or operational issues that might not seem obvious at first?

We have a loco we wish to maintain a backdated look on, and one option being investigated is to re-mount the air pump in a different location, that is less obvious to the public. We recognize that re-locating it will complicate the daily inspections, but we're considering all options at the moment

Check valves may not function in a horizontal plane. Check valves that I have seen are gravity sensitive. The air check valves would have to be spring loaded or reed valves used in some commercial air compressors.

You are probably better off to locate the compressor (single cylinder Westinghouse type?) concealed on the tender, in a vertical orientation. I seem to recall hearing about this being done on a loco restoration. The additional piping for steam and discharge air would be a bit of trouble, but much less than trying to make a compressor function in a horizontal location.

Howard P.

Yea, they need to be vertical. IIRC, Delaware & Hudson mounted the air compressor between the frames on an engine that they were trying to get a very clean look on.

I believe Swanton Pacific had their compressors mounted horizontally on the deck of their tenders. They looked to be full size compressors.

Might be worth reaching out to someone on that team and see what struggles, if any, they encountered.

A lot of locomotives in the UK have had air compressors mounted between the frames also.

I'll be darned. I just pulled up old video of the Swanton Pacific, and yup, there's a standard single air compressor up on top of the tender deck, sideways and horizontal.

Locomotive is 1912, 19" gauge.

I would have said no until I saw this...
https://dai.ly/x5mxg9q

When the tender's rockin' don't come knockin'!

Yeah, it looks full scale but perhaps not Locomotive. WABCO made pumps for other steam related uses, some of which were smaller........ still, given the option I'd rather go vertical as designed if possible.

Louis MacDurmot approached WABCO about obtaining plans so that he could build scale down versions of their smallest air compressors. They wouldn't agree to that, but sent five 8" single compressors. The side tank locomotive had the compressor mounted vertically on the side of the smokebox. From what I have gathered he did the same with the Pacifics. The mounting of the compressors on the tenders came after the Overfair Railway.

True!
Snagged from Google.