Hunting an 'Antelope'

[Sanjay F]

Hi everyone

I need some help locating the drawings for a Plastows Antelope engine for which I have acquired the castings. Plastows were bought by Stuarts some years ago, but unfortunately Stuarts informed me they did not not get the drawings for any of the stationary engines when they bought Plastows, only the traction engines 

Here are some images of the complete engine and the castings - any drawings or more information regarding this engine would be wonderful, thank you 

[Jasonb]

It's not going to win any prizes for looks. The extended steel base plate with space for something else suggests it was designed more for those that wanted an engine to do something rather than be looked at. The mention of layshafts, pulley sizes and belting would support that.

Bit unusual as it looks like there are no steam passages in the cylinder instead steam goes from the ports into pipes and then to the ends of the cylinder

[Sanjay F]

I agree, I think I'd scrap both the metal and wooden bases and have the engine sitting only on its suports under the cylinder, trunk and bearing mounts may be on a nicely shaped piece of wood, also lose the brass tanks.

Can someone check my homework, I have tried to ID the parts and not sure if they are correct and some bits I have no idea. Also where is the crosshead?

Is that a thing to have pipes going into cylinder ends from a steam chest rather than directly via steam passages, I've never seen it before?

I've just noticed flanges both sides of the valve chest with the valve rod poking out?

[Jasonb]

It does say the crosshead is cast iron so it does look like the part ???? on the top row but I would sat maybe only half of it is needed.

I don't think the bronze castings you have listed as sheaves are the sheaves, I think the two iron castings on thebottom row are sheaves. They may have had a flange on the boss side with teh actual running surface being a smaller diameter. Then the bonze castings fit on teh other side and trap the strap between them and the flang ethat is integral to the sheave.

Aluminium part is more likely a second pully as it is too big to be a cover which you seem to be missing one of.

Very unusual to have pipes instead of passages. I've seen a couple of engines with nice castings that do a similar job but not piped. Might be possible to drill some passages if the cylinder walls are thick enough.

[Jo]

Pic of another set of Antelope castings attached.

Should be easy enough to make without drawings 

Jo

P.S. DO NOT BUY THESE THEY ARE ON A SCAM SITE

[Jo]

You have most of the names right Sanjay  So naming the Castings from the top left:

Cylinder (with integral stand),  Crankshaft bearing/stand, Trunk Guide, Iron Cross head, Pump Sheave and side cover, Connecting rod, Two cylinder covers and second Sheave and side cover.

Lower row:

Pulley for driving round belt, CI Eccentrics, Water Pump, Pump ram Flange and top cover, Crank throw/web,  ??? Pump accessories or piston rod/valve rod glands? , valve chest/cover/valve, Piston, Flywheel.

There should also be the piston rod and valve rod glands somewhere in the bits I labelled as for the pump.

Normally where pieces run together dissimilar materials are used so CI runs on Bronze, so cross head is CI in a Bronze guide. I assume the piston is not the same bronze as the cylinder, an Ali piston might be a better choice. Bronze sheaves run on CI eccentrics.

The Eccentric Sheaves are solid circles so they need side plates to keep them on the eccentrics or screws into a groove on the eccentric. As these are a bit small the side plates would be easier.


Never seen an engine with pipes going to the cylinder ends. Very unusual. 

Jo

[Sanjay F]

Thanks Jo for the second ID parade, very helpful 

Ah yes, now both you and Jason have mentioned the eccentric sheaves I have seeen that type of 'sandwiched' sheave before; I can't remember where though? I haven't got the castings to hand yet, but should do by the end of the week, so will have a better idea and be able to upload some more images for the catalogue

........and as for the scam site, what a bargain at £32 for a set of castings which you'll never get! 

[Jasonb]

I'm still not sure you have the two cylinder covers on the top right.

Looking at the diameter of the flanges on the cylinder the one with the gland boss looks far to small a diameter to fit .When you get the castings can you take a measurement of it's diameter and also that of the cylinder flanges.

It is possible that the smaller one with the boss fits inside the end of the trunk guide and then the flange on the end of the trunk guide is what fits to the cylinder flange's larger diameter. It's not a common way but I did do one engine with something similar

[Jasonb]

Thinking about it  abit more the spigots on th eend of the cylinder may be the clue.

Rather than turn the end flush right across the flange the spigot remains, the smaller gland cover fits on the end of that and the trunk guide slides over th espigot/cover and fixes to th elarger cylinder glange. Just got the added complication of steam into the flange to think about

[Sanjay F]

Thanks Jason, that's a thought, I did wonder why there was so much material on the ends of the cylinder casting - I can tell this one's going to be 'interesting' - Let me measure up the bits and post my findings

[Sanjay F]

So the Antelope arrived in a huge very heavy box - I thought there was an actual antelope inside

It came wrapped in a copy of The Sun newspaper from 1986 which gives a good clue as to when it was bought (Page 3 was missing BTW ) The castings are very nice and solid and larger than I expected as you can see. Included in the pack was a beautiful piece of brown coloured Formica  which will not be kept, but the also a very large piece of steel plate 0.200" thick and some brass sheet which may not be used on this engine but will be definitely kept.

Amusingly, the reason for the names of their engines was supplied in the pamphlet (see below) so I'm going to keep the 2 steam feed pipes going from the valve chest to the cylinder when I build it just for authenticity! 

I have now reached out on other model engine forums to see if anyone has the drawings and my wife has done the same on social media. I don't feel confident enough atm to take on this engine without the drawings especially as no one seems to know anything about it or has built it.

It's under the bench for now, but hopefully someone, somewhere will track down the Antelope 

[samc88]

Will you keep the disc flywheel or go for a more aesthetic version?

Looks an interesting engine, especially with the piped steam chest, not seen that done before. I wonder what the reasoning was behind it, its probably more work getting neat pipes than drilling steam ports

[Sanjay F]

Not sure tbh, it does look rather clunky and I must admit a traditional spoked flywheel would definitely be an improvement. I think the Ali pulley wheel could also do with a brass replacement! As Jason pointed out it isn't the prettiest engine, but I think with a few changes and mounted onto a more traditional box bed would improve matters significantly .......a strange beast indeed

[Jasonb]

If the Gazelle came first with it's two pistons in the single cylinder than that would have been a more likly reason for the pipework rather than ports to get that going. So if the Antelope followed as a simplified single then the pipes would be a throwback to the earlier gazelle. The excessive length of the cross head points to the same casting being used for both engines so others are also likely to be shared between the two engines.

Plastows used to be known as Lion Engineering hence the logo. If you read his book Plastow was fond of a traction engine named Lion.

Now that the Looks like the unknown casting is the glands for the poston and cylinder rods as you can see the ocal shape better in the latest photo.

I did ask on ME forum for you but no joy.

[Sanjay F]

That would make sense re. the pipework and other components being shared between the engines. TY for askng on the other forum, I'm sure someone somewhere will have these drawings tucked away!