Boxhill Terrier Build Notes

Hi All,

My name is Bob Thompson and I am new to the forum.

For the last 4/5 years i have been building and running 16mm steam locomotives and have decided that before i depart this planet i would like to have a go at building something a bit bigger.

I have decided that I rather like the look of the 5" gauge Boxhill Terrier as designed by Martin Evans.

Now my question.

I have a set of drawings, but Martin serialised the build notes in Model Engineer in 1963/64 and these are too old for ME to search out.

Does anybody have a copy or access to this series of articles??

Bob T

Hi Bob,

I photocopied the original articles when I made my Terrier in the early 70s. I am sure that they would copy again and I would be happy to take them to the nearest Staples (?) and copy and send them to you at cost. They run to about 90 pages - some of them have my own notes on (which you can ignore!).

If you do go ahead with your model I don't think you will be disappointed. They perform as well as the original! Please be aware that a recent thread on this forum has highlighted some of the errors in the drawings which you should be aware of.

Please advise if you want me to go ahead.

Dennis

Hi Dennis

Thats excellent news thank you. If its not too much trouble I would be delighted to receive a copy as you suggested.

Im not familiar with the forum protocol yet so not sure if you do these sort of things "off group" or not?

Either way if you let me know the cost as soon as you know I will whisk off payment by return.

Do you know the title of the thread referring to drawing errors?

Bob T

Bob T.

You may be intertested in a thread called <Any "Beginners" building 5" gauge Boxhill?>

This was started back in Oct and has had many replies - the last one a week ago. It may be worth a search. I tried to be clever and give you a direct link but couldn't find out how to do it!

Barry Q

Thanks Barry Q sounds like thats worth a look

BobT

Hi Bob

The thread identified by Barry is the one I was thinking of. Also, if you search for "Boxhill" in the thread titles for this forum you'll see several others.

I'll send you a private message when I have copied the articles.

Thanks Dennis i look forward to hearing from you

Bob T

Hi All,

I am about to fit the wheels to my Boxhill. I have succesfully quatered and pressed on the front and rear wheels.

When it comes to the driving wheels and the quatering of the same, what is the position relative to the crankshaft. The crank leads on the right hand side by 90Deg so are the wheels in sync with the crank or do they lead the crank by 90 or 180 Deg ???

Many thanks

Bob T

hi bob,

the Terriers have Stroudley's pet arrangement of balancing... the crankpins on the wheels are in line with the cranks, and not opposite. the balance weights are opposite the cranks which is why the balanceweights are quite big. by the way i wouldnt personally press on the crankaxle to the wheels and always loctite mine, to avoid damage to the crankaxle. dont forget to put the axleboxes on first if they arent split! (mine are split as per fullsize).

cheers,

julian

Thanks Julian, I knew i could rely on you and thanks for the tip, i was a bit concerned at applying all that pressure to what is a relatively delicate assembly. My boxes are not split but yes i was wary of pushing ahead and leaving them off, easily done.

Cheers Julian

BobT

hi bob,

before you put the driving wheels on, make sure there isnt excessive clearance between the inside of the axleboxes and the outside of the crank webs. martin evans' dimensions have excessive sideplay allowing the crankaxle to move sideways by quite a large amount. about 10 thou each side is all that's required, otherwise you will get excessive wear on the eccentric straps and conn rod big ends.

good luck!

cheers,

julian

Thanks again Julian

Bob T

Hi Julian,

Me again with a couple more questions if you can help?

Firstly can you advise on size of drain cocks ( as in thread size)

Secondly do you know what duty injector is suitable for Boxhill?

Thanks and regards

Bob T

hi bob!

drain cocks 3/16 x 40 tpi. the positioning of the cylinder cover bolt holes can be improved upon from the drawings, and if you havent machined the cylinders to drawing you will need to offset the drain cocks as done by norman barber in his excellent construction series (there isnt enough metal on the bottom of the cylinders to fit them where they should be). in fullsize the draincock linkeage is sort off attached to the front guard iron by an extra bracket and then goes up, then along, to the rear L-H cab box underneath the L-H running board. well worth fitting 5 cylinder drain cocks... 4 for each end of the cylinder and one for the rear of the steam chest. if you want to make them yourself LBSC's 'Live Steam' book/'Shop Shed and Road' tells you how with drawings. unfortunately martin evans glossed over cylinder drain valves on BOXHILL.

the smallest commercially available injector is 12 oz per min which should be suitable (try Polly or Blackgates, usual disclaimer, and you may have to order well in advance). ive got to make up a batch for STEPNEY when i get round to it, and 2 will be fitted to mine as i cant stand axlepumps or crosshead pumps!

cheers,

julian

Thanks Julian,

I have already machined the cylinders and covers and drilled for the fixing bolts. Just got the tricky bits on the underside of the bolting flanges to do.

I took a print of Norman Barber's drawing showing his drain cocks so hopefully can get it right. I take it the 5th drain cock would go on the underside of the steam chest at the rear end and linked to the same linkage.?

I too had thought to get rid of the pump, presumably a similar take off from the turrett would be needed for the steam and the second injector connected to the other clack.

Many thanks

Bob T

hi bob,

yes the steam chest drain cock would go on the undersideat the rear and connected up to the same linkeage for the cylinder drain cocks.

the manifold/turret martin evans designed for BOXHILL is pretty awful! it wouldnt be difficult to arrange for a second steam valve for a second injector. note however that the fullsize Terriers didnt have a manifold/turret. injector steam valves (when later fitted) were on the boiler barrel either in front of the dome or just behind, and would only be correct with the A1X rebuilds with the Marsh boiler. however, either side of the water gauges were 2 backhead valves, and these could be used as injector steam valves with pipes inside extending forward and up, if you didnt want to fit a manifold/turret. it is well worth having a look at a fullsize Terrier backhead to see how beautifully everything is arranged and proportioned! then you will realise what a mess martin evans made of BOXHILL's backhead! (he did the same with FIREFLY around the same time too!)

cheers,

julian

Thanks Julian,

I see a Trip to the Bluebell looming,

Thanks for your help enjoy the sun

Regards

Bob T

Wow Thanks for that Julian

Bob T

have a look at

http://www.bluebell-railway.co.uk/~uhaa009/bb/pics/terriers.html

which is where the above pic came from.

as might be expected the Terriers underwent numerous detailed changes over the years, as crosshead pumps were replaced by injectors, and vacuum brake ejectors fitted in addition to the westinghouse air pumps, but essentially Stroudley's original arrangement and design was retained. Boxhill has been faithfully restored to original condition in the NRM. note also in the above link of pics how the martin evans reverser is nothing like fullsize, and note the rectangular firehole with 'Webb' type door, and the large radius to the backhead. the curved cover over the backhead actually acts as a saddle and has the tanks bolted to it, taking their weight, which is why there are no brackets to speak of underneath the running boards. note also the 'quadrant' type water valve handles in each corner half way up the front spectacle plate... these originally controlled water from the tanks to the pumps, and were re-used when injectors were fitted.

cheers,

julian