7mm An APT in 7mm

Jim S-W

Jim S-W

Western Thunderer
iploffy said:
in the near future I want something different so I started thinking and came up with the ultimate big boys train, the APT. Now there is a couple of slight snags with this no-one produces a Mk4 body shell and no-one produces SIG style bogies
Click to expand...

I wouldnt worry about the lack of a mk4 coach as the APT was nothing like them anyway (completely different shape). It didnt run as a full set much either so you could get away with a shorter rake. It would be pretty cool though.

Cheers

Jim
 
Dikitriki

Dikitriki

Flying Squad
I do admire the thinking big aspect of this project. I'm about 1/2 way through a LMR BP, and the 6 coaches of that is more than enough for me. 14 would send me nuts.

Richard
 
mickoo

mickoo

Western Thunderer
I'm with Jim, APT body is no where near Mk4 shape, APT cant rail width is much narrower to allow for the tilt and not go out of gauge.

I have a set of schematic drawings somewhere if your interested and a reasonably accurate coach cross section, two books you may consider if you proceed.

APT, A promise unfulfilled, Hugh Willaims Ian Allen
Advanced Passenger Train , Avon AngliA Publication

The drawings are in Modern Railways, cna't remember which one with out digging out the relevant pages.
 
marsa69

marsa69

Western Thunderer
Stu Fox said:
14 coaches @ 75 feet - thats a scale 21 feet (ish)
Click to expand...

I'll go halves with him and we can have 7 coaches each :p

As for the power cars would it not be better to twin motor each power car keeping them in the middle as per the prototype? I would imagine that with suitable ballast in the other coaches any derailments could be reduced,

Mark
 
iploffy

iploffy

OC Blue Brigade
As for the power cars would it not be better to twin motor each power car keeping them in the middle as per the prototype? I would imagine that with suitable ballast in the other coaches any derailments could be reduced.

Although I like the idea of following the prototype to the letter I am not convinced that pushing bespoke irreplaceable coaches is either a wise of sensible thing to do. The train will lack the sheer mass to be able to keep it on the rails, all it needs is a small piece of ballast in wrong place or a slight rise in one side of the 4ft and a tumbling down to earth they will go. It's only my personal opinion but you are only moving one of the motors out to the extreme end of the train
 
D6356

D6356

Western Thunderer
Hi gang ,
A little search on Shapeways reveals a T gauge version under development ! might be worth some consideration!
certainly a lot shorter than lengths suggested! but perhaps the designer can share files
Robert
 
lancer1027

lancer1027

Western Thunderer
Hi guys
his is an interesting thread and one i will be watching.
Although im not particularly interested in the prototype , i am very interested how this will be built.

Looking forward to progress on this:thumbs: RoB:)
 
Jim S-W

Jim S-W

Western Thunderer
Hi iploffy

I would say it depends on if you want to run overhead or not. By that i mean i have pondered this for tring and the idea of push pull rakes doing 90mph (in p4). It would be easy to power the pushed rakes via the DVT with a dummy AC at the back but the worry is if the loco derails the train could concievably carry on while the pan does all manner of unpleasantness to the overhead.

With an APT then you have a similar worry with unpowered power cars in the middle of the train. You could power the ends and pick up though the center cars but if it ends up as light as you think it might do you want the forces either end acting on the middle? Id guess (and it is just a guess) that you would have bigger crashes powered at the ends than the middle.

Thinking a bit more, how about powered power cars but pick up the power from the driving cars. That way if the driving car derails the power is cut?

Cheers

Jim
 
iploffy

iploffy

OC Blue Brigade
I understand where you are coming from but with 14 coaches I really think that the motors would be better spread throughout the train rather than in 2 coaches. There is another train (excuse the pun) of thought if you get a double motor bogied locomotive and have a pulling competition with a single motor powered loco which one will win, (this is an example not comparing different types and makes of motors)obviously the one with more power. If you take the higher powered idea and move one motor to the extreme end of the train that is pulling half as hard, where as the other is pushing half as hard connect the 2 electrically then you have the same as a loco but evenly spread. so for arguments sake if it did derail the front motor would be pulling it so lessening the power pushing it. The 4 motors will be spread like this,

up=un-powered bogie
p=powered bogie


drv coach trailer trailer trailer trailer trailer power power trailer trailer trailer trailer trailer drv coach
p +..... up ....+up ....+up.. +up .....+up.. + up. p+up. up+p. up...+ up.....+ up...+ up...+ up.....+ up + p
 
Stu Fox

Stu Fox

Western Thunderer
I believe the Scots weighted the driving trailers on the pushers with concrete? (the 47/7 ones). It seems to be an issue of weight at the front with sufficient power to move the whole shebang... ...reminds me of the 33 + 4TC we used to hurtle around the South Western with. It may be worth a study of the research by the southern on push pull dynamics - they seemed to crack it - the basic physical forces (although sizes will differ) are the same (aren't they?)

Regards

Stu
 
Jim S-W

Jim S-W

Western Thunderer
Was that after the Polmont disaster?

Havent seen the hornby pendo Jordan. Does it have the now standard hornby motor bogie that pivots from the top? If so it probably rocks for and aft, their southern EMU has the same problem. Although a single powered bogie in something like a pendolino is pretty poor these days.

Cheers

Jim
 
mth

mth

Western Thunderer
Ian
You are trying to over complicate things. With the 2 motors in the middle, one will be pushing 7 coaches the other will pull, and it wont matter which way the set runs. With what you are saying, your idea you mean you will be only able to run it one way.
 
mickoo

mickoo

Western Thunderer
Stu Fox said:
I believe the Scots weighted the driving trailers on the pushers with concrete? (the 47/7 ones). It seems to be an issue of weight at the front with sufficient power to move the whole shebang... ...reminds me of the 33 + 4TC we used to hurtle around the South Western with. It may be worth a study of the research by the southern on push pull dynamics - they seemed to crack it - the basic physical forces (although sizes will differ) are the same (aren't they?)

Regards

Stu
Click to expand...
Correct the DBSO on the GEML were very bouncy so I think some more weight was added up there when they got here for 100mph running to give better stability. The new DVTs are a heavier vehicle which helps that as well.

Don't forget the 4REPs as well 3200hp in a four coach EMU pushing another 2+4TC at high speed.
 
iploffy

iploffy

OC Blue Brigade
Yes I can agree with the weight issue as the west coast Dvt had a massive weight under the nose. Another take on it was GatEx they used a powered luggage van as the Dvt with a motor left in from when it was a unit. It's this idea that appeals the most
 
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