Abstract: A tool for more quickly and efficiently removing the liner bolts that hold sections of liners to the inside of an ore grinding mill shell. The tool has thick-walled tubular barrel with a front cap assembly and a rear valve assembly at opposing ends. A projectile is slidably disposed in the barrel chamber. The rear valve assembly connects to a supply of compressed air to deliver compressed air to the chamber and cause the projectile to move rapidly forward toward the front end cap assembly and contact an impactor, which is in contact with the liner bolt to be removed. The forward movement of the projectile causes the impactor to move forward and drive the bolt out of the shell and liner. The tool has little recoil effect and utilizes a safety absorber to reduce the likelihood of damage or injury from use of the tool.

Abstract: A railroad crosstie is constructed from at least two individually distinct rail support blocks interconnected by a web system which is fastened to the blocks and which comprises at least one self-supporting rigid sheet member adapted to be buried in the roadway ballast when the tie is in place. The blocks are selected to support and secure rails in conventional manner, and the interconnecting web system holds the blocks in relative position in the roadbed. The rigid sheet member adapted to be buried in the roadway ballast is advantageously disposed or provided with means such as horizontal longitudinal corrugations to interact mechanically with the particles of standard railroad ballast, whereby the tie resists being withdrawn from the roadbed.