==== Модон боомт ====
[[File:Dam Timber Crib.jpg|thumb|left|
A timber crib dam in [[Michigan]], photographed in 1978.]]
[[Timber]] dams were widely used in the early part of the industrial revolution and in frontier areas due to ease and speed of construction. Rarely built in modern times because of relatively short lifespan and limited height to which they can be built, timber dams must be kept constantly wet in order to maintain their water retention properties and limit deterioration by rot, similar to a barrel. The locations where timber dams are most economical to build are those where timber is plentiful, [[cement]] is costly or difficult to transport, and either a low head diversion dam is required or longevity is not an issue. Timber dams were once numerous, especially in the North American west, but most have failed, been hidden under earth embankments, or been replaced with entirely new structures. Two common variations of timber dams were the ''crib'' and the ''plank''.
''Timber crib dams'' were erected of heavy timbers or dressed logs in the manner of a log house and the interior filled with earth or rubble. The heavy crib structure supported the dam's face and the weight of the water. [[Splash dam]]s were timber crib dams used to help float [[logging|logs]] downstream in the late 19th and early 20th centuries.
''Timber plank dams'' were more elegant structures that employed a variety of construction methods utilizing heavy timbers to support a water retaining arrangement of planks.
=== Бусад төрлүүд ===