Marine M4A3 Sherman “Tokyo Express” of the 5th Tank Battalion in ditch Iwo Jima
The 5th Tank Battalion developed its own unique modifications for protection and camouflage during the Battle of Iwo Jima. Instead of using the more common birdcage armor over the hatches, which was employed by the 4th Tank Battalion to defend against grenades, the 5th Battalion adopted an innovative approach by welding penny nails to the roof areas of their tanks. This tactic was intended to disrupt the placement of satchel charges or other explosive devices that Japanese infantry might attempt to throw onto the vulnerable tops of the tanks.
Additionally, the 5th Tank Battalion utilized wooden skirts over the tank’s suspension to help deflect the satchel charges that Japanese soldiers frequently tried to place underneath the tanks. These skirts acted as a physical barrier, helping reduce the risk of damage from close-quarter attacks.
In terms of camouflage and visual identification, the battalion adopted a relatively simple color scheme. Many of their tanks were painted in a golden brown color, possibly U.S. Army Earth Yellow, over the usual olive drab or dull dark-green base paint. This simplified color scheme was different from the more elaborate camouflage patterns seen elsewhere.
Regarding identification markings, while the UNIS (Unit Serial Identification System) was not widely used by the 5th Battalion on Iwo Jima, many of their tanks did feature a two-digit number inside a square, typically painted on the upper-right corner of the front differential housing. This marking could also appear on the side of the tank, the turret, or the rear plate. Even when overpainted in some areas, these numerical markings were key for identifying specific tanks within the battalion. For example, Tank 52, as mentioned, still had its front marking visible on the differential housing despite the overpainting elsewhere.