Brunel Viaduct

[Moonraker]

I am just starting the construction of a five pier, Brunel wooden trestle viaduct. Can anyone suggest the best type of wood strip to use in conditions of almost continuous sunlight, little rainfall and temperatures up to 40 centrigrade?

Peter

 

[coyote97]

oh, didnt find infos about a brunel viaduct.....can u help?

i have a bunch of wood here that awaits to be built to a bridge, ..

my experience with spruce-wood are so-and-so. when not constantly wet and not too small diameters (10mm or less) it works.
beech wood does not go well.

we will use larch for our constructions. Therefore we ordered many as a seperatly production order. What u can buy in the homeworks-market is mostly spruce or pine....mmmm..not the best choice i think.

Frank

 

[stockers]

If you can find it use Cedar. It is very oily which works well as its own preservative. Otherwise tanalised softwood. Get heartwood (middle of tree) if you can. Sometimes refered to as Red wood. (nothing to do with the redwood tree).

 

[coyote97]

http://www.pendleburymodels.com/

ey

nice church

Frank

 

[simon@mgr]

If you have a table saw you could cut your own timber, using something like jarrah, expensive, but no chance of rotting.

Moonraker is in South OZ

 

[stockers]

jarrah, expensive, but no chance of rotting.

That will work great - if you can find it.

 

[CoggesRailway]

my local model railway museam has a beautiful model of a brunel viaduct http://www.pendonmuseum.com/dartmoor/index.html
in it's self it is historic being in service carrying model trains for well over 50 years!

 

[simon@mgr]

jarrah, expensive, but no chance of rotting.

That will work great - if you can find it.

Very common in Oz

 

[coyote97]

uhh...funny construction...but very interesting

 

[corgi]

Hi Peter, I built my tribute to Mr. Brunel (see Pic.) using well seasoned OB hardwood (eucy. regnans) for the three main beams, and treated pine for the inclined bents, and decking. There is a better type of treated pine, not using the old copper process. I tend to buy it in the form of decking boards (70x20). The bents are nailed and glued, I confess I didn't even use water-proof glue, then gave the whole thing a liberal coat of sump oil. It's been outside now for 3yrs. and is as good as the day it was put out there. It hasn't warped, split, or moved in any direction. I is a removeable section and has to line up with 4 pins and never fails to do so. Having used a lot of jarrah in my life, I have found it surface checks (splits) within 45mins. in the sun, when used in small cross sectional areas, such as you would use in a bridge, larger pieces no problems, though I would suggest a bit overkill regards choice. PM me if I can help you with any details,
Grant.
PS bridge in full sun all day.

It might move if I climb over the back fence and borrow it.

 

[Moonraker]

oh, didnt find infos about a brunel viaduct.....can u help?

Frank

Frank,

I have good information on Brunel viaducts. I am building mine to a scale drawing of the Walkham viaduct by C.J.Freezer in the March 1953 Railway Modeller. There is also a great article on building a G Scale Brunel-style fan trestle in the November 1995 Railway Modeller. Finally, I have photos of an absolutely sensational, ten pier Brunel fan trestle in Gauge 1 taken from the Model Railway Constructor but I don't know the date.

I could scan these and post them on this forum but am not sure about copyright rules.

Peter

 

[coyote97]

seems this kind of bridge have some interrest...hmmmm....
Thanks for all the sources!

Frank

 

[stockers]

There is a better type of treated pine, not using the old copper process. I tend to buy it in the form of decking boards

The old copper, chromium and arsnic (CCA) preservatives have been banned in the EU and possibly further afield. Tanalising solution is now based on insecticides and biocides. Rot is actually a fungus, so the right biocide should kill it.
Your decking boards have most likely been tanalised, a vacuum and pressure treatment process.

Link to Tanalith site:
http://www.archchemicals.com/Fed/WOOD/default.htm

 

[Budd]

Peter, you might want to try Merbau, a rot resistant hardwood used for out door furniture and suits our Adelaide climate well, after construction regularly give it a coat of Linseed Oil, the timber will eventually go grey, you can buy it as decking boards and rips down nicely, it has a very straight grain and is pretty stable.
Wayne H

 

[coyote97]

becoming grey is a matter of growing old...both with timber an humans..

i think its fine when wood turns grey....it does in "original", too.

We will use larch with our wooden bridges. its not easy to get in the fitting measurements, therefore we ordered a special. But thats fine.
Larch has much resin what makes it some kind of "inside-resistant".

U have to be aware, that ALL kind of wood goes away, depending on where it is used.

There is wood that cracks while becoming too dry, other wood moulds while getting just a bit wet. Therefore it is important to use a fitting wood, available, affordable and stabile. With the use of dry (drainage-ed) abutments, it willwork for a WHILE.

That brunel-bridge is very interesting....i think we will produce one just to find out if there is some interest on it....
...it looks just great, that construction.

Nice. like it.

Frank

 

[Woderwick]

I am about to have 50sq metres of 15mm thick Hevea Parawood floor torn up and replaced due flood damage. So I shall be keeping the some of the old stuff for structures. I wonder if the cheaper hardwood floorpacks would be an option?

 

[coyote97]

i would be careful with old wood......it doesnt like hard changes, and wood from an old floor may deteriorate..deretroid..derero... may collapse very fast. Especially when it first faced a water-problem....ummmmm...... 8|

Frank

 

[Woderwick]

Mebbe, but its worth a go. Its only 3 years old and its a seasoned hardwood, worth a try methinks.

 

[coyote97]

only three years?--ok, that is no prob.
Thought you are talking about a 80 year old floor.....

Frank