Original sentence: Replacing flat bottom girder rails on sleepers and ballast with LR55 in tunnels can increase the head room by a minimum of 300mm, without the need to excavate the tunnel invert.The same rail has been tested to 80 tonne axle loadings for mainline use, and can be used in tunnels and other locations where the loading gauge is restricted.These can include double deck passenger trains and freight trains with high cube (10ft 6in - 3200mm) maritime containers
Edited sentence: Replacing flat bottom girder rails on sleepers and ballast with LR55 in tunnels can increase the head room by a minimum of , without the need to excavate the tunnel invert.The same rail has been tested to  axle loadings for mainline use, and can be used in tunnels and other locations where the loading gauge is restricted.These can include double deck passenger trains and freight trains with high cube ( ) maritime containers