This is a little bit more complicated conversion. On this Mk an exhaust silencer was fitted with an exhaust pipe leading to the rear. Another improvement was that the petrol tank was located outside the vehicle to reduce the fire risk.
Unditching beam stowed on top of tank
The unditching gear.
The Mk IV was equipped with unditching gear, this consisted of a heavy wooden beam carried on rails on top of the tank. If the tank became stuck in the mud the beam could be fitted to the tracks with chains.The beam would then be pulled over and under the tank by the tracks so freeing the tank.
Spuds fitted on every 4th tracklink
Mk IV tracks.
Like the Mk II the Mk IV tank had tracks with spuds, in this case spuds were fitted on every 4th tracklink. Pictures of the Mk IV Tadpole Tail show that this vehicle had tracks without spuds.
Mk IV female and male sponsons
Mk IV sponsons.
Like the previous Heavy Tanks the Mk IV came in a male and a female version. The sponsons were redesigned, they were much smaller in size and could be swung inwards. This avoided the time consuming bolting on and off of the sponsons for railtransport. The 6pdr gun of the male version had a shorter barrel compared with the earlier Mk's.
Lengthened tail, designed to be fitted on Mk IV and Mk V tanks to increase their trenchcrossing capabilities, they were never used in action.