ABSTRACT
There are various ways of joining pieces of timber together – pegs, dowels, keys, nails, screws, bolts, connectors and glue. The connection problem is more difficult when large forces are involved, as for example transmitting horizontal shear force in built-up beams. The development of glued-laminated timber beams after strong, durable glues were invented during the Second World War would seem to have solved the problem. In 1967, a book entitled Wooden Structures edited by Professor G. G. Karlsen was translated into English from the Russian and published in the West. It revealed that timber technology in the USSR was remarkably advanced in some respects. The Derevyagin beam, invented by V. S. Derevyagin in 1932 and described in Wooden Structures, uses oak keys, proportioned for maximum efficiency to connect the separate pieces of a built-up beam with no glue. The use of glue is now being questioned on health and sustainability grounds. The Derevyagin beam, an elegant piece of engineering, shows that it is possible to make built-up timber beams without the use of glue.
