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Discussion Starter · #1 ·
I am redesigning some of my bridges and would like to know the heaviest loco on the large scale market today. I am assuming that the Big Boy would be the heaviest but I may be wrong. Some of the new diesels are pretty heavy and I know that live steamers are up their also.


Since my total system includes two 4-6-0s' and an old 0-4-0 I don't have much to go on.


I need to know the heaviest so I can test the new designs.


 


Thanks for your help.
 

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When I build a bridge for my previous layout my wife specified that it should be able to take the weight of our son (2) who did walk over it. So I designed one to take 40Kg... IT BROKE. Not because of the weight of Matthew but rather the point loading of the structure. My heaviest loco is 12.75Kg. The lift out bridge will be designed to take 40Kg as before -but the point loading will be 4Kg. Stan has said that his "BigBoy" weighs 80lbs -but that is spread over quite a few axles -whereas the 12.75Kg will be spread over only 4 axles -giving a point loading of 3.18Kg.

regards

ralph
 

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While not the heaviest, a long bridge has to take the weight of multiple lashups of diesels.

My Sd-45's are over 15 pounds apiece, so 4 of these exceed 60 pounds.

USA's largest steam engine with tender goes over 35 pounds so a pair would be over 70 pounds.

Make the long bridges very strong, or support them in the middle.
 

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My K-36 weighs 40 pounds and is 3'-6" long.
Are you going to do structural calculations?
If so how do you calculate the joints.
Maybe just consider load testing with masonry blocks.
My bridges seem to carry a great deal of weight, but they did move a bit when I leaned an extension ladder against them to trim a tree.
 

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My SD45 is 20 pds each.
Important part is build a bridge so it won't sag..over time.
 

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Discussion Starter · #7 ·
Thanks all for your thoughts and suggestions. I had no idea a Big Boy weighed that much and I hadn't even thought about multiple lash up's of diesels.


My engineering department is run by a guy named Pete, Primitive Pete that is. I will probably use Dick's method of calculations, stack 80 lb. of bricks on it and if it holds up we are pretty safe. I did that with a truss bridge once when a customer asked about it. I stacked forty lb. on it and it didn't even budge. It's always amazed me how much weight you can but on a truss structure if its made right.


What else are you looking for in a vintage style of bridge? Remember I need to keep them simple so that the cost is not out of sight.


Thanks all.
 
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