Graham Ind. TVR1A

logoman · Graham Ind. TVR1A

I finally got a camera and took some pictures of my TVR1A. I'm now making some small modifications to both manifolds, and so one is missing in the photos.

You probably know from Moose's great build log that it's a Twin cylinder, Vertical, Reversing (TVR) steam engine with a 1/2" bore and 5/8" stroke, and Hackworth reversing gear.

During the build I needed some extra bits, and the service I received from Robert Graham was outstanding.

After I'd had the pleasure of building and rebuilding the engine a couple of times, I came to feel that I had not bought the engine, but that I'd paid $245 for short course in understanding steam power, and that the engine was a gift at the end. This was because Mr. Graham has a special talent for writing instructions in a style that is both clear and encouraging.

I decided to paint the engine, and after a couple of colour changes, settled on black. I used the VHT Flameproof paint.
The only problem I had was on the steam chest, where it was necessary to use a base coat of acid etch primer.

I paired the TVR1A with a Cheddar (Stuart) 3500 boiler, performance is very controlable, and self starting and reversing have never failed.

If you haven't built an engine, and aren't a machinist, but fancy a having a go, I can't recommend the Graham Industries engines enough.

regracing

shiny

CuriousSteam

OMG!!
A must get!!!
The paint work is outstanding!! Great Job

Keith S

I don't understand how the hackworth valve gear works

.

Does the notched post on the side mean it has variable cut-off as well as reverse? I've seen it on model locomotives and it looks to me to be sort of like a single-eccentric stevenson link but with some walschaerts and singer sewing machine thrown in for good measure. It makes my brain hurt, although it does look cool with all the mysterious moving parts. I'm not a clever man. I'm sure it's quite simple in reality. I've never seen one.

Bugsy

kusuchi

Very impressive, Miles.

An outstanding result.

johnreid

Oh my, that is nice. They make nice engines, Benji showed me his Graham Shay engine last week, it was so impressive.

mogogear

GUTMACH

Dagnabit John, you did not have to go use the word SHAY !!!

Anyhoo, very nice engine, and great paint job.

Wayde

Les

A lovely engine with a great paint job.

calypso

Beautiful looking engine Miles.

I've been considering getting one of Graham's engines for a while now.

I finally ordered a VR1A a few days ago. Can't wait for it to arrive.

I just hope I'm up to building it.

johnreid

As I understand, the Shay is a discontinued item
Bens engine, Owens photo

logoman

Thanks for all the response guys, I really appreciate it. The great thing about this forum is that seeing everyone else's steam wonders makes me aim that bit higher in my own projects.

logoman

rangerssteamtoys

Here is a video of an engine with the same valve gear,

Its pretty simple.

Bugsy

logoman

rangerssteamtoys

I watched all his videos about steam engines, he looks to be a nice guy and makes some good engines.

Keith S

Ranger, what a nice video. I hope I am like that old man when I'm...well, old. I keep warning Mrs. Keith to get her ready for the day I disappear into the basement forever to build steam engines. I should show her this video.

Logoman, as I understand variable cut-off, the reversing levers of more detailed or larger slide or piston valve engines have intermediate positions between full forward and full reverse. For starting, the eccentric throw moves the valve over its entire travel and the ports open for the longest possible time during each stroke. As the reversing lever is moved into intermediate positions, the travel of the slide valve becomes shorter and the ports are open for a shorter period of time, allowing less steam into the cylinder during each stroke. This allows the smaller amount of steam to expand more fully during the stroke of the piston and therefore makes more efficient use of the thermal energy of the steam. The engine uses less steam per revolution and less heat energy goes to waste in the exhausted steam. It does however lack the impulse or "punch" that it would have if the valve were open for the longest possible amount of time. I have heard it compared to the gears on a car: having the reversing lever fully over in the reverse or forward direction is like being in first gear: lots of torque but inefficient as the engine moves faster, as the cutoff is increased (by moving the lever closer to neutral, there is less impulse or torque due to less steam initially entering the cylinder, but greater effieciency due to the cylinders' being able to extract more energy from the expansion of the steam, thus it is like moving into a higher gear. It works differently than just shutting the regulator because the valve events are still letting steam in at the same pressure, just for a shorter period per stroke as cutoff is increased. Models with variable cutoff can also be throttled to some extent with it too, because there is a "neutral" position between forward and reverse where the valve wouldn't move at all.

That's the longest explanation I've ever written and it might be pure bollocks, but this is what I think "variable cutoff" is. Most of our models do not have this and are therefore wasting steam at high speeds by operating in "first gear" all the time. If you were to shorten the stroke of your valve, the engine would be more difficult to start and would accelerate very slowly, but it would use less steam and be more thermally efficient. If a model engine were to have this feature it would be a nice engine indeed

logoman

pure bollocks? pure clarity me thinks, a superb description and exactly what happens when using with the Hackworth gear. Thanks for explaining it so well Keith, I couldn't have begun to describe the efficient use of steam in the cylinder.
Before he retired a few years back, my father designed engines for Formula 1, I don't want to imagine what he must think of me and my steam engines.

mogogear

Miles, I have to bet your father is in the PROUD category...without steam engines , internal combustion engines would have had a very slow birth and maturation process. Everything has a ancestor.....

mogogear

logoman

yes Mo, Alabama I think. he does sell his engines on ebay.

rangerssteamtoys

Variable cut off is acheivable on Jensens that have stephensons links. Variable cut off is just an energy saver once you get going.

Keith S

Actually here's a good video giving an example of it. It's a traction engine but you can see the driver moving the reversing gear, reversing the engine, and he opens the regulator with the cut-off nearly at neutral, and then moves the cutoff (reverse)lever all the way forward, and opens the regulator again. You can really hear the difference in the exhaust sound.

http://www.youtube.com/watch?v=zGj1elA2HoA

CuriousSteam

Keith that was some explanation!!! But you know what, I understood it. Long but clear. Thanks

Bugsy