Over the past few years, I have occasionally come across the odd larger piece of Royal Marine weapons training on Woodbury Common.
This is a 3.5 inch M29 practice anti tank rocket, which would have been fired by the M20 rocket launcher. This is a dummy/practice round used for target training and it must be stressed that it isn’t live!!! These rockets from the common can be identified as harmless practice rounds by the bright blue paint on the warhead section. A live High Explosive version is dark Olive Drab Green – fortunately I haven’t come across one of those!
The rockets I’ve found usually date to the 1950s and are marked with the makers initials ‘TH’ for Royal Ordnance Factory Thorp Arch, Yorkshire. The one above was made by ROF Chorley, Lancashire in May 1963.
The M20 rocket launcher was an American weapon, first being issued in late 1944. The British began using it in 1950, replacing the WW2 era PIAT gun (Projector Infantry Anti-Tank). The M20 continued to be used until the 1970s when it was replaced by the 84mm Carl Gustav recoilless rifle. The early American High Explosive rockets contained Composition B Explosive but the later/British ones had RDX. The 3.5 inch Anti-Tank rocket launcher was developed by the US military at the end of WW2, replacing the much smaller 2.36 inch M9A1 rocket. The design was loosely copied from the WW2 German Panzerschreck launcher. The 3.5 inch M28 High Explosive rocket had a shaped charge of 9lbs of RDX high explosive, which was capable of penetrating up to 11 inches homogeneous armour plate.
The warhead section of the practice rounds are made of cast iron and are entirely hollow, with the fuze/detonator section being made of a solid construction aluminium alloy (3.5 inch M29 practice rocket diagram below). The rocket is fired electrically. In the pistol grip of the launcher is an actuator arm connected to magneto. Wires in the rocket nozzle would be connected to the contactor plate of the launcher when loaded into the tube. These three rocket motors are empty as there would be wires protruding from the nozzle if it were live!
Below are pages from a 1950 training manual of how the M20 launcher works.
Over a year ago, I decided to restore a broken practice rocket that I found, and make it into a lamp. These rockets are 2ft long and this example was in the same condition as the broken rocket at the top of this page. After nearly 2 months of grinding, filling in rust holes, sanding, priming and painting, it looks tremendous!
The last picture are of Royal Marine recruits firing the 3.5 inch M20, which I’m pretty sure might have been taken on Woodbury Common.
Dalditch Camp, History, And Finds on Woodbury Common, Devon. 