Disappointed by UK train horns. Help me make some real noise!

Hey all,

I’m Matt from the UK and i have a pair (hi-low) of Desilux horns, made in London for use on our Class 37 diesel Loco’s, as per the attached pics.

I’m currently running them from a very small, all-in-one chinese compressor (1 gallon), using 4mm pipe and compression fittings. The tank is full at 120psi, so it has more than enough pressure to operate these things, albeit not for very long!

Can anyone tell me what thread the horns use, as i’m currently using a crappy chinese solenoid, which happened to screw straight into the horn. One of these…

And yes, i know the tank is not really up to scratch, but once i’ve bought all my fittings/pipe and the sound makes it worth investing in a viair, i will buy one, but at the minute i can get a good 3-4 second blast before the compressor kicks in.

Help me make the most of these beautufully crafted horns! :smiley:

Pics attached

Welcome. I’m not familiar with those horns, but most any set of horns is going to benefit from a bigger airline than 4mm.

The solenoid you linked has specs in the description.
Air Outlet: 1/4"NPT-MALE
Air Inlet: 1/8" NPT FEMALE
Includes a 1/4" BARB Fitting for 1/4" ID Hose.

Wecome to the forum. Check stinkypete’s site - ukhornstar.com (I think). Maybe he can help.

Cheers Dan, its “hornstaruk” like Pornstar lol lol:D

Hi Matt & welcome to the forum & good to see another UK hornblaster.

The Horn you have was manufactured by a company here in London called SECOMAK AIR PRODUCTS - Honeypot Lane, Stanmore in London.

I have one myself, but have never been a r s e d to connect up an airline to it.
I found a thread on another diesel web forum talking about diaphams etc etc & then found a link to someone auctioning off a pair of them for £180.



I am not really sure myself what thread they are? Best thing to do is take it to somewhere like Plumbase, they have a specialist section of the company that just do pipe fittings & the name escapes me completely at the moment. I will remember later as I drive by the place!

I will unscrew the adapter that goes into mine later when I get home and see if I have anything that fits or is close to fitting.

Cheers, Pete.

Hi Pete,

Thanks for the reply. It turns out that they do in-fact use the 1/4" NPT fitting. What i found confusing was that the thread looks considerably bigger than 1/4" (6mm), but a 1/4" NPT thread has a diameter of 13mm - work that out if you can…

Don’t get me wrong, it makes a bit of a racket, but not nearly as much as i expected.

I’m thinking, maybe i should try some of this, along with some 10mm fuel hose.

But this poses a problem as to what solenoid i’m going to use that will flow enough air to the horn and not be a bottle-neck in the system.
Maybe i could use your 1/2" solenoid, but use a ‘step-up’ from 1/4" to 1/2", then into your solenoid, then back down to 1/4 and into the horns?

That’s the other thing - I have 2 of these horns. Will 10mm pipe for instance be large enough to supply them both?

Yeah, I don’t know whether you saw my reply to you on ebay, my valve simply screwed onto my horn using a 1/2" to 1/4" reducer. 10mm hose should be fine for them, the solenoid would go into a manifold where they then split into two to feed the horns. I’ll see if I can rig something up when I get home.

Thanks pete! That’s a great help.

Now all I need to do is part with 30 quid and hope that upping the size of the fittings will make it sing…

Don’t suppose you had chance to hook it up to an airline?

Sorry off topic, but the sound of a class 37 = ♥

I’ve got the lovely job of designing and speccing an ETCS system to fit the class 37 and also the 97.

…the joys of working for network rail! :rolleyes: