Land Mattress was a curious hybrid an army weapon constructed from an aircraft rocket motor and a 5-in naval warhead. Early models were severely restricted in performance since elevation was restricted between 23 °and 45 °.
Loaded and ready to fire, the crews make their final checks before taking cover. Fired at a rate of four a second, half the rockets from a 32- round projector would hit a target zone 215 m (235 yards) long and 219m (240 yards) wide.
Although early development of the war rocket in the United Kingdom was initially to produce an anti-aircraft weapon, some consideration was also given to producing an artillery rocket. One early attempt at this was a design for a 127-mm (5-in) rocket which was rejected by the army but adopted by the Royal Navy for use in modified landing craft for the saturation of landing beaches and approaches by massed rocket fire. This eventually evolved as the ‘Mattress’, but range was limited. However, further trials revealed that the range could be improved by introducing, at launch, a degree of spin which would also improve accuracy, and this was simply achieved by using an aircraft 76.2-mm (3-in) rocket motor attached to a naval 13-kg (29-lb) warhead. This increased range to a possible 7315m (8,000 yards), making the artillery rocket a viable proposition once more. Thus ‘Mattress’ became ‘Land Mattress’.
The Land Mattress, a multi-barreled rocket launcher was the brain child of Canadian artillery officer Lt. Col. Eric Harris and perhaps more than any other Canadian weapon of the war demonstrates not just ingenuity but versatility. Necessity is often called the mother of invention and war the crucible of progress, in late 1944 Canadian forces fielded a rocket launcher that demonstrated both these philosophies. The first prototype of what would evolve into the Projector, Rocket, Three Inch, Number 8, Mark I, better known as the Land Mattress was originally the brainchild of a British officer, Lt. Col. Micheal Wardell. While serving in North Africa, Wardell’s unit was engaged by German forces and in danger of being overwhelmed.
He successfully convinced a nearby anti-aircraft battery to direct their rocket projectors against the enemy. The results were impressive and broke the enemy’s morale, though it actual effectiveness was not determined at the time aside from turning back the assault of course. Wardell returned to England and using the Naval Mattress generally used for amphibious landings as a template for his multiple rocket launcher he developed a prototype. In early 1944, he demonstrated his projector to the representatives of the British War office at Larkhill’s British School of Artillery. His prototype suffered from a number of deficiencies which the British were unable to overlook. The general consensus was that the system had merit but it would take up to two years to fully develop. While the War Office may not have been interested in Wardell’s prototype, Harris, who had been invited to attend the demonstration as an observer, was. The Canadian officer had been interested in rocket projectors for some time and in fact had attended similar a demonstration in 1943 which led to Canadian officers officially being assigned to the British Rocket Research Establishment. Harris invited Wardell, with the blessing of the War Office, to develop a Canadian prototype. Wardell, Harris and the First Canadian Army enthusiastically set about creating the system and drawing upon all the knowledge and favours they could to do so.
The First Canadian Army set a number of guidelines and requirements on the project which made it a challenge to complete. First and foremost was an ingrained reluctance in artillerymen to embrace the opportunities a rocket system held over artillery pieces. There was also some resistance amongst the English to release the equipment needed to develop, test and outfit the rocket projectors, which was no doubt exacerbated by the fact that the system would be combining parts from a number of shall we say unique sources. Harris and Wardell demonstrated a resourcefulness driven by desired function and an abundant supply of equipment discarded or deemed inadequate by other services.
The prototype launcher was largely a unique piece of equipment designed from the ground up, but the rocket was a Frankenstein creature. The rocket was of course unguided combining a 29lb Royal Navy warhead mounted on an Air Force 3” rocket and topped by an Army base detonating fuse. Two 40 tube launchers were built as a proof of concept and in June 1944 a single test salvo was launched at Aberporth, Wales achieving a maximum range of 8,250 yards. A second salvo was fired in July which resulted in the project receiving the go ahead to begin operational trials.
The first army launchers for these new Land Mattress rockets had 32 barrels, but a later version had 30 barrels. Demonstrations of this launcher greatly impressed Canadian army staff officers, who requested a 12-launcher battery which in the event was ready for action on 1 November 1944, This battery went into action during the crossing of the River Scheldt and was a great success, to the extent that more were requested and produced. The Land Mattress launcher was limited in its elevation capabilities to between 23 and 45°, and this not only limited the maximum range to 7225 m (7,900 yards) but also limited the minimum range to 6125m (6,700 yards). To reduce the minimum range possible, a system of rotary spoilers over the rocket exhausts was formulated and put into use. The rotary spoiler disturbed the exhaust gases by closing off their efflux by varying amounts, and thus reducing the minimum range to 3565 m (3,900 yards).
For all the success of the Land Mattress, not many equipments were used in action before the war ended in Europe in May 1944. By that time many were only just emerging from the factories ready to be sent off to South East Asia, but their use there was very limited, as a result mainly of the weight and bulk of the projectors in the area’s jungle conditions. A special 16-barrel version was accordingly developed for towing by a Jeep, but the war was over by the time it was ready for service.
In action, a single Land Mattress projector salvo could result in 50 per cent of the rockets falling in an area 215 m (235 yards) long by 219 m (240 yards) wide. The rockets were fired in ripples at 0.25-second intervals so that the entire salvo could be fired in 7.25 seconds. During the crossing of the Scheldt the first Land Mattress battery fired 1,146 rounds over a six-hour period. As each warhead payload weighed 3.18 kg (7 lb), the effects can well be imagined.
|Weight||1,118 kg (2,465 lb)|
|Shell||Rocket length: 1.77 m (5 ft 10 in)
Rocket weight: 30.5 kg (67 lb)
Warhead: 3.18 kg (7 lb)
|Caliber||76.2 mm (3 in)|
|Muzzle velocity||353 m/s (1,160 ft/s)|
|Maximum range||7,230 m (7,910 yd)|