Nick Dunhill's 7mm workbench.

mickoo

Western Thunderer
The turbines are mostly outside the frames, on the drivers side is the forward turbine with six jets and about 1/4 projects inside the frames, on the firemans side is the reverse turbine with three jets and is completely on the outside, the gear box is inside the frames and links the turbines via drive shafts and clutches through the frames.

The LMS Turbine Locomotive

And a photo from the magazine mentioned above I expect.

http://www.model-engineer.co.uk/sites/7/images/member_albums/93892/618573.jpg
 
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OzzyO

Western Thunderer
Ozzy

At any scale speed, the model wheels would be doing the same rpm as the real thing.

6'6" = scale 45.5mm diameter, which is nigh on 143 mm circumference.

90mph = 1.5 miles per minute, 2413 metres / minute, which scales as 55.5 metres per minute

390 rpm x 0.143 = 55.77 metres / minute, so near enough.

Best
Simon

Hello Simon,

I do appreciate that the model wheels would be doing the same RPM as the full size loco, so are you saying that for a scale 90MPH that the loco / train would have to do 55.7Meters per Minute? Or approx. 165' in a minute.

The turbines are mostly outside the frames, on the drivers side is the forward turbine with six jets and about 1/4 projects inside the frames, on the firemans side is the reverse turbine with three jets and is completely on the outside, the gear box is inside the frames and links the turbines via drive shafts and clutches through the frames.

The LMS Turbine Locomotive

And a photo from the magazine mentioned above I expect.

http://www.model-engineer.co.uk/sites/7/images/member_albums/93892/618573.jpg

looking at the drawings of the forward turbine it's not that big (long), only say 3' then you would have the drive gear on the end as well. So to produce the H.P. it must have been a very good power plant.

For some reason I had always thought that the turbines were between the frames, not just the gearbox.

OzzyO.
 

mickoo

Western Thunderer
Hello Simon,

I do appreciate that the model wheels would be doing the same RPM as the full size loco, so are you saying that for a scale 90MPH that the loco / train would have to do 55.7Meters per Minute? Or approx. 165' in a minute.



looking at the drawings of the forward turbine it's not that big (long), only say 3' then you would have the drive gear on the end as well. So to produce the H.P. it must have been a very good power plant.

For some reason I had always thought that the turbines were between the frames, not just the gearbox.

OzzyO.
No it isn't and like wise they look small to me, but a browse of rail mounted turbines in genereal shows them to be rather small units globally.

If you think about a normal steam engine, the piston is actually quite small as well, take 19" in diameter and a 20" stroke, physically it's even smaller than a turbine, of course a four cylinder loco has four of these to help it along, but overall it's not a big surface area when you think about it.

Where the turbine gets it's power from is clearly the gearbox, a small low power high rpm unit coupled to a large high ratio gearbox can do an awful lot of work, think mountain bikes, I've seen people cycle easily up grades you'd struggle to walk!

Mick D
 

SimonT

Western Thunderer
These turbines aren't driving a chuffing great fan and sets of compressors to drive the turbine or having exhaust gasses used to provide some of the thrust.!
 

Pencarrow

Western Thunderer
Good to meet you today Nick towards the end of the Telford show. We had a good chat about the Bulleids on show and novice kit building. Still in awe of your work.
 

simond

Western Thunderer
Nick - great to meet today, and a joy to see your models.

Ozzy, sorry not to have found you over the weekend. Sorry also that I missed your post 14/7 regarding the scale speed. Er, yes, I think I am saying 55 metres per minute - 3 feet per second or so, so a train of say 10 coaches would take something like 5 seconds to pass

Best
Simon
 

simond

Western Thunderer
Yes Dan told me that was the place to look, but my timing wasn't good - and I had an impending 4 hour drive :(

Best
Simon
 
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