2½" Gauge Canadian Switcher by P E Hunt

[John Baguley]

I briefly mentioned this some time ago when I described making a new smokebox front for it.

To go into a bit more detail -

I bought this loco from Ebay just before Xmas last year (my excuse was that it was a Xmas present to myself!). It came up for auction and I instantly recognised it as a Canadian Switcher to the design by P E Hunt, a Canadian contemporary of LBSC at the time who had designed a few 2½" Gauge locos. These are very rare and I doubt if more than half a dozen have ever been built. A couple appeared in Model Engineer and I later found that this particular loco had been built by Roy Simmons, a member of the Bristol Club and a very early member of the N25GA. The loco actually appeared at the very first rally held by the Association in 1975 at Cheltenham.

I am not sure if the chap driving in this next photo is Roy Simmons himself

It has been suggested that the chap behind may be Don Young with his daughter Elaine. Perhaps Julian may be able to confirm or otherwise?

A photo taken at Cheltenham in 2009

Anyway, I decided to buy the loco to at least keep it within the Association and with a view to restoring it back to running condition. it was partially dismantled and unfortunately, some of the original parts had got lost. The cab was missing along with the running boards, the axle pumps and a few other parts such as the dome covers and chimney. At least the major parts were still all there. The tender was still complete. The loco is extremely well made so should be a pleasure to work on.

Apparently, Roy decided to start doing some maintenance work on the loco and began to dismantle it. He then passed away and whoever cleared his workshop probably didn't realise that some of the loose parts belonged to the loco. How does often does this happen!

Loco as received:

Not long after receiving the loco I ran the chassis on air and it runs extremely well on just a few psi so that's a good start. I have now had the boiler tested and that is fine as well.

So far as I know, the drawings for this design disappeared a long time ago apart from a GA drawing that appeared in Model Engineer in 1929 and couple that the Association have. One for the cylinders, which are a two piece design incorporating the smokebox saddle and one for the valve gear that only has a few of the dimensions on it. Roy did make a pattern for the cylinder blocks that he donated to the Association so we still have those. The driving wheels are from Kennions and I think they were for the LBSC design Lady Kitty.

The above photos are the only guide  I have to remake the bits that are missing so the finished item may not be exactly as Roy originally built it.

I did make the new smokebox front to replace the missing one. That was a pleasant turning job from some bits of bronze silver soldered together but fitting the dummy studs and nuts was a bit tedious. Thank heavens for the DRO on the mill!

As there are very few drawings left for this design I have decided to reverse engineer this loco, make a 3D CAD model and then produce a new set of drawings that will be made available through the Association. I will incorporate what I consider to be a few improvements in the new drawings. The new design will not be an exact copy of the original P E HUnt design but a mixture of that, Roy's design and my own ideas.

At present the loco has been stripped down to it's basic parts and a lot of the 3D CAD model has been completed. Once I have what I need from the individual parts the loco can be rebuilt as time permits.

The original did have an injector fitted and it looks as though it went on the front of the tender which meant having a flexible steam pipe to the tender and another flexible pipe for the feed to the boiler. I will change this and refit an injector on the loco as normal. Also, the pressure gauge is on the top of the tender tank which again required a flexible pipe to the tender. I'm going to fit an ordinary gauge in the cab!

A few images from the CAD Model so far:

More to come soon hopefully.

John

[davewoo]

Lovely engine John, I have seen it once before years ago and remember it went very well, it is indeed a rare bird, the late Ted Benn had the bare bones of one. From memory just a rolling chassis with no cylinders, but I think it had a tender, no idea what happened to it when he disposed of his engines. A great idea to reverse engineer into a set of drawings, with a nice wide firebox and plenty of adhesive weight an ideal small engine for 2 1/2" gauge. Good thing I don't really do ebay or there would have been another bidder!
Dave

[jma1009]

Hi John,

Definitely not Don Young and Elaine in your second pic. The guy your refer to is then driving the loco in your 3rd pic.

Cheers,
Julian

[John Baguley]

Thanks Julian,

I would have been surprised if it was true.

Regards,

John

[johnd]

John,
You probably have seen it but just in case there is another photo of the loco in the steaming bay in ME V144 1978 issue 3594 P1153 “1978 21/2” Rally”

[jma1009]

It does look to be a very nice loco!

I've always been quite keen on USA locos!

[John Baguley]

Jul 17, 2022 18:14:32 GMT johnd said:

John,
You probably have seen it but just in case there is another photo of the loco in the steaming bay in ME V144 1978 issue 3594 P1153 “1978 21/2” Rally”

Thanks John,

I hadn't seen that photo. It's interesting to see the photo lower down where Roy is raising steam with a bicycle pump!

Julian - yes, it's definitely one of my better acquisitions. Most of them require throwing half the bits away and making new!

Dave - it was listed as a 'Buy It Now' but because I was watching it the seller sent me a price that was quite a bit lower so I succumbed!

I'm curious as to what the tank is under the LH running board. It has a filler on the top and a small diameter pipe running forwards. I don't think it's a lubricator as there is a mechanical one between the frames underneath this tank.

It's a bit of a mystery as to where the whistle should go as well. The steam from the whistle valve goes to another hollow stay in the boiler and there is an elbow on the LH side of the smokebox that I presume should be connected to this hollow stay and then to the whistle. I did wonder if the tank on the LH side was actually the whistle?

Unfortunately, I don't have a good enough photo of the front of the loco to show the axle pumps. Roy fitted these under the smokebox at the front and they are driven by eccentrics on the middle axle via a rocking shaft which doubles the throw of the eccentrics. I've just had to guess here and have drawn up something that will fit.

For the new drawings I have fitted the axle pumps to the motion plate and driven them from the rear axle which will be much easier:

Here's a photo of the cylinder assembly partially dismantled:

They would be an interesting exercise to machine but fortunately I don't have to!

I don't intend to modify the valve gear on the original unless absolutely necessary. I want to try and keep it as original as possible. The valves do appear to be slightly too long though as the valves do not open until a few degrees after the dead centres so I will probably reduce the lap by shortening them. I'll check this when I get the chassis back together.

John

[mbrown]

I wonder if the tank was a hydrostatic lubricator, later replaced by a mechanical one but left in place for appearance sake?

At the time the design came out, displacement lubricators were very commonly specified in 2.5" gauge.

Malcolm

[John Baguley]

You could well be right Malcolm. The thought had crossed my mind.

John

[doubletop]

John

This photo of yours does demonstrate how nicely made the loco is



Envious

Pete

[John Baguley]

Hi Pete,

Yes, it's nice to work on something like this for a change. Most of what I seem to do entails a complete rebuild or rework. Sometimes it would be easier and quicker to scrap the lot and start again!

John

[GWR 101]

Great work John, I wish I could undertake that quality of workmanship particularly in that scale. I struggle with 3 1/2", afraid the fingers don't work as well these days. Might I see you on the 7th?, always a pleasure. Regards Paul

[John Baguley]

Hi Paul,

Yes, I will be there on the 7th. Always a good day out

I struggle with the smaller stuff nowadays as well - due to both fingers and eyesight. 5" is easier to work on but too heavy to move around!

John

[liftnerd]

Would you like some pictures of the real thing? I visited Conway Scenic Railroad last week. Canadian National 7470, an O-18-a, part of the class that the 2.5" Canadian Switcher was modeled from, was in the roundhouse undergoing some boiler work. They let me in, so I took some pictures.

liftnerd