Large Scale Central

Trestle template

GAP said:

OK answers to some suggestions and more description

  1. Korn could you please shed some more light on this statement “now comes the interesting part. for the trestles to stand straight, when everything is finished, they have to be fixed a 3.5° inclinated to the beams.” is this because the bridge is on a grade?

just that.

for the observer standing in front of it, the ground goes up from the left to the right, while the deck of the bridge goes down from the left to the right. (both at 6% grade)

thus the vertical trusses build no right angle with deck or ground. the leftmost trestle is 40cm high (nearly 16"), the rightmost one is 8cm high (about 3").

my bridge is not broad enough, because i had little space for the footing.

in general:

don’t forget, what i forgot. these trestles had some little platforms sticking out from the sides, for barrels with water.

make the trestle as big, as possibly fits in the space avayable. size matters - and distracts from sloppy building.

Just remember one piece at a time

(https://www.largescalecentral.com/public/user/18f8d/18f8d_59e3.jpg?c=559e)

Well a complete rethink has taken place and the double trestle idea has been shelved for now, it was going to be so resource hungry that a large percentage of my hardwood would be consumed leaving nothing for anything else.

The local garden centre has hardwood stakes of a length and dimension that will work for the posts so they will all be made of these while the sills, sway braces, cap etc will be made of the hardwood (just need to cut it, how hard can that be?).

On another tack what is the recommended track centre spacing for 2 parallel straight tracks?

Track to track spacing in inches needs to be referred to scale. I would make my minimum 13 scale feet, but be careful on curves that you get the tracks apart to a much larger spacing before the curve.

Greg

GAP said:

On another tack what is the recommended track centre spacing for 2 parallel straight tracks?

I personally like or prefer a 5.75 inch minimum spacing to a 6.75 inches of maximum spacing (O/C of the parallel tracks) on the straights. However it also floats in the section shown above. I also prefer to “run or model” cars that have body mounted couplers which have a maximum length of 37.5" inches to a minimum length of 8 " . Everyone’s railroad is different within G scale and there is really no standard answer to your question as far as I’m concerned.

Edit because I forgot the " . " after straights and before however didn’t have a capital H after the period so I had to correct that as well but it’s all fixed and sorry for the misunderstanding !

Using an online calculator 13 Feet in 1:20.3 scale (my largest) it works out to be 7.6847".

So somewhere 6.75" and 7.69" will work looking at that I think I use 9" between track centres and 5" away from the fence posts that the shelf will be screwed to should give me plenty of clearance.

I thought I read somewhere years ago that 8" was a sort of standard but evidently that is not the case

Thanks to all for the suggestions.

I use about 9-1/4" but I am 1:29, and that is my mainline spacing. I understand that prototype minimum spacing in yards was about 13 scale feet.

So I did specify in my responses minimum… for typical mainline, clearly it should be larger.

This page has some real-world examples, as it varies between countries: https://en.wikipedia.org/wiki/Track_spacing

Greg

Greg Elmassian said:

I use about 9-1/4" but I am 1:29, and that is my mainline spacing. I understand that prototype minimum spacing in yards was about 13 scale feet.

So I did specify in my responses minimum… for typical mainline, clearly it should be larger.

This page has some real-world examples, as it varies between countries: https://en.wikipedia.org/wiki/Track_spacing

Greg

Thanks Greg I have 2 scales 1:20.3 and 1:22.5 (LGB) so the 9-9.5 should give me heaps of clearance.

Another question;

What spacing between bents on a trestle do people use?

I’m doing some calculations to see if I have enough timber to make one about 10’ long.

GAP said:

Another question;

What spacing between bents on a trestle do people use?

I’m doing some calculations to see if I have enough timber to make one about 10’ long.

i put one every 15cm (6"). worked fine for me.

I usually space the bents the same distance I use for the stories, so the sway bracing makes a nice even X

So whatever the distance is between the top horizontal piece and the next horizontal piece below it is the same distance I use for the bent spacing.

GAP said:

Another question;

What spacing between bents on a trestle do people use?

I’m doing some calculations to see if I have enough timber to make one about 10’ long.

On mine I went with 6" and some shorter on the opposite side to give me the curve …

GAP said:

Another question;

What spacing between bents on a trestle do people use?

I’m doing some calculations to see if I have enough timber to make one about 10’ long.

I agree with the other guys on the 6" spacing.

David Maynard said:

I usually space the bents the same distance I use for the stories, so the sway bracing makes a nice even X

So whatever the distance is between the top horizontal piece and the next horizontal piece below it is the same distance I use for the bent spacing.

I went with the 6" spacing as well, but soon removed the X sway bracing when I discovered the leaves could easily get in there, but I could not reach my hand in to pull the leaves out. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)

Bruce Chandler said:

David Maynard said:

I usually space the bents the same distance I use for the stories, so the sway bracing makes a nice even X

So whatever the distance is between the top horizontal piece and the next horizontal piece below it is the same distance I use for the bent spacing.

I went with the 6" spacing as well, but soon removed the X sway bracing when I discovered the leaves could easily get in there, but I could not reach my hand in to pull the leaves out. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)

I didn’t go with X sway bracing for the same reason

(https://www.largescalecentral.com/public/album_photo/11/a7/01/1a46b_20f2.jpg?c=2ea6)

(https://www.largescalecentral.com/public/album_photo/13/a7/01/1a46d_3779.jpg?c=3278)

I know, but it just looks better to me with the sway bracing.

David Maynard said:

I know, but it just looks better to me with the sway bracing.

It looks a LOT better…but, when the leaves are in there, it doesn’t look nearly as good. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)

That is why there are no sway braces on the bottom story. So I can get my hands in there and remove the leaves.

Funny talk, mesquite leaves are tiny and laff at your worries. They go where they wish.

On a curved trestle I include all sway braces. On a straight contained between two earthen berms or sturdy ends some sways are not needed and saved for repairs, by order of our cheep management.

5 finger sky cranes are shot on sight.(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)

PS: I have 0 trestles at the moment.(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

Some more questions;

  1. For the bents what are the dimensions that folks used of each individual upright post.

I have 19mm (about 0.75") wide timber and was thinking of just ripping it to make 19mm square pieces, would they be too large?

  1. What dimensions are the horizontal pieces across the top between the bents, looking at the pictures they appear to be the same as the posts that make up the bents, is that correct?

  2. What dimensions were used for the bracing timbers, looking at the pictures they appear thinner than the other timbers, I’m thinking about 19mm x 9mm (0.35") does that sound OK?

I did a rethink about my trestle location and it will now be a curved one to take a line around a corner and down a grade.

It starts at 16" high and goes down to about 2.5" and will be about 84" long. It will be built on an elevated frame about 2.5-3 Feet off the ground.