The sleeper is manufactured from wood at first. The wood has good elasticity and insulation. It is less affected by the temperature change of the surrounding medium. After anticorrosive treatment of wooden pillow, service life is also greatly extended, in 15 years or so. Sf the world's railways use wooden pillows. According to statistics, during the peak of the use of wooden pillows, more than 3 billion pieces of wood were laid around the world and most of them were pine. You can imagine how many forests have to be destroyed As forest resources dwindle and people's awareness of environmental protection increases, of course, thanks to the development of science and technology, some countries began to produce steel pillows and reinforced concrete sleeper in place of sleeper in the early 20th century. However, because the metal consumption of the steel pillow is too large, expensive, bulky, did not spread, only a few countries such as Germany are still in use. Since 1950s, many countries began to produce reinforced concrete sleeper.
轨枕起先采用木材制造，木材的弹性和绝缘性较好，受周围介质的温度变化影响小，重量轻，加工和在线路上更换简便，并且有足够的位移阻力。经过防腐处理的木枕，使用寿命也大大延长，在15年左右。所以，世界上90%的铁路都使用木枕。据统计，在木枕使用高峰期，全世界大约铺设了30多亿根而且大多数是松木。可以想见，这得毁掉多少森林？随着森林资源的减少和人们环保意识的增强，当然也因为科学技术的发展，上世纪初，有些国家开始生产钢枕和钢筋混凝土轨枕，以代替枕木。然而，因为钢枕的金属消耗量过大，造价不菲，体积也笨重，没有推广开来，只有德国等少数国家还在使用。而许多国家从上世纪50年代起，开始普遍生产钢筋混凝土轨枕。
