[john g]

Has anyone got the hornby suspension bridge. my daughter has one, we will be putting it on the layout when we get the chance and space. it will be on an 8' x 4' running on a 3rd rad curves. working on a 4.5ft approx. incline, from start of incline both sides. it's an 8cm / 80mm hight to reach. my mathmatics is zero, would a hornby clan line climb this with a rake of about 4 pullman coaches.

thanks for any help

john

 

[Doug]

distance is 4.5ft = 54" = 137.16cm

height is 8cm

137.16 / 8 = 17.145

incline is roughly 1:17 which is quite steep.

It would be best to double the distance on the up-ramp. Perhaps use a loop around the back to slowly raise the track to the bridge height.

 

[dwb]

I thought that the percentage for 1:17 would be ~6% (1/17)?
Which ever way you look at it, 1:17 is still pretty steep. I seem to remember that the old Triang track plan book for Super 4 track had a plan specifically for the suspension bridge.

David

 

[Doug]

David - I removed the miscalculation to prevent confusion.

Yep, it is quite steep. 1:40 is more suitable for a model railway layout.

 

[john g]

thanks doug & dwb,

i was reading about the skaldale coal shute and ramp. being put together, in the hornby magazine. i think they said about 3.5 feet for the incline. that was needed, looking at the picture of the shute & the ramp for it looks very steep for it. we have decided to use just half of the bridge as we would not have enough room/space for a more gradual incline. so thanks again lads.

john

 

[neil_s_wood]

The incline is something you really want to get right before you make it permanent. I made a big mistake with this on my last layout by buying the bridge, which was far too high, first and trying to get locos to get up the steep gradient. Initially I could only get them up the gradient by revving them at full throttle which was not the best idea. Eventually I got a bridge to fit in with the gradient which was a more succesful idea and things worked better after that. With this experience in mind I have pretty shallow inclines on my new layout and when I want a high bridge I drop the base board by the amount I need.

 

[ozwarrior]

John, just be aware that the bridge is 1372mm/54" long itself!

 

[dwb]

QUOTE I seem to remember that the old Triang track plan book for Super 4 track had a plan specifically for the suspension bridge.

I found the Super 4 track plan book in the attic. The plan is number 9 and it is designed to fit in a space 8' 10" x 5' 1". The suspension bridge is laid diagonally across the layout from the outer loop. The R457 inclined piers set for Super 4 track had 7 elements to raise the track to appropriate height. At a guess the plan allows about 6 feet to raise the track to the height of the bridge.

It is important to remember that those were the days of "Magnahesion"® when chassis mounted magnets gave locomotives extra traction on the steel rail. There's a promotional photo under the Magnahesion logo on page 3 showing a 4-4-0 tender loco at the head of 2 and half coaches. My guess is 3 coaches were all you were expected to run in a space 8 x 5. Certainly that's all I ran when I was restricted to that space. I always longed for that suspension bridge but could never justify the cost or work out how to make it fit with the double track main line I have almost always modelled.

David

 

[Mike Button]

"would a hornby clan line climb this with a rake of about 4 pullman coaches."

I've recently installed a gradient to a fiddle line on my layout, also took the Hornby suggestion of 1 in 17 as a starting point but after some good advice on this forum ended up with about 1 in 40. My Princess, which I guess has the same chassis as your Merchant Navy runs up this with six following with no problems. Good luck!