10 October 1940. Dorset, England.
Lulworth Camp, the Armoured Fighting Vehicle School of Gunnery, was well used to Valiant tanks coming and going. As more Royal Armoured Corps Regiments were equipped with the tank, passing their final gunnery school was an important stage in preparing them for operational readiness.
Today however, was a noteworthy day as the first Valiant Mark II had arrived and been tested on the range. This was the first of three Mark IIs expected. During May the new QF 6-pdr 7 cwt gun had gone through its trials. Vickers had been given an order to make 14 pilot models of the gun, specifically for tanks with the shorter L/43 barrel. Vickers had been preparing a redesigned turret for the gun and its ammunition. Now that they had a few guns, it was ready to be tested on the range.
The first prototype Mark II turret differed from the Mark I in a number of ways, not least that it was a bit wider, some extra inches had been added to increase the angle of the slope of the armour on the sides of the turret, so that it had a passing resemblance to the turret designed for the cancelled A13 Mark V Cruiser (Covenanter). This prototype also differed from the Valiant Mark I with the addition of a cupola modelled on the German Panzer III and IV. The decision to delete cupolas from British tanks had been done because of the fear that, if hit by enemy fire, it would take the commanders head with it. The fighting in France and Flanders however had shown that tank commanders were more likely to sustain injuries by sticking their unprotected heads out of the turret to see what was going on. When the German tanks had been examined and tested, it was felt that the advantages of the vision blocks outweighed the possibility of it being struck by enemy fire.
The tank commander in the Mark II turret had the standard Vickers periscope Mark IV in addition to the cupola, and it was hoped that between these two, would help with his awareness of what was happening all around the tank. For troop or squadron commanders, this situational awareness was particularly important, as was communications. The Mark II turret also included the new Wireless Set No 19. This had three channels. The A channel provided communications within the squadron or regiment. The B channel, with a shorter range was designed to work within the troop of tanks. Finally, there was an Internal Communication channel, or IC, which allowed crew members within the tank to communicate. These radio sets had only just gone into production and the Valiant would be the first tanks to be equipped with it, as Vickers had designed the turret for, but not with it. As the numbers of radios increased, they would be retro-fitted into the Valiant Mark I and I*. The tank commander who had the first experience in the new turret in his initial report stated that he felt that the radio, once he was used to it, and the cupola, gave him the ability to command the tank effectively.
The gunner noted that the 6-pdr gun had a completely geared elevation, and no longer needed his shoulder to lay the gun, just as with the Valiant Mark I. The pre-war doctrine of firing on the move was being reviewed in the light of the experience of the fighting in France and Flanders. Vickers, when they had designed the turret for the 6-pdr gun, believed that the weight of the gun, its balance, along with the pull needed by the gunner to fire the weapon, would all militate against accuracy in firing on the move. The geared elevation, it was believed, would permit the gunner the best means to hit required targets. The gunner on the initial test found that the elevation and traverse controls were accurate and fast enough to satisfy him. The gunner noted that the sighting telescope fitted, a No 22, which was adapted from the old 18-pdr was very poor, and had no markings for using the co-axial Besa machine-gun. A new, and better, sighting scope was needed as a matter of urgency.
The loader was the one whose job in the new turret had changed most of all. The 2-pdr shell was easy to handle with just one hand and around one hundred rounds were carried. The 6-pdr shell was three times heavier and needed more dexterity and muscle power to get it from the stowage bins to the breech of the gun. At the end of the exercise, he noted a greater tiredness than he would have experienced using the smaller gun, but also added that it hadn’t affected his ability to load the gun. The larger shell meant that only 64 rounds could be carried, down a third from what they were used to. This was noted as something that might be improved. It was also noted that while there was less ‘elbow room’ in the new turret because of the bigger gun, it didn’t affect the ability of the crew to fight the tank.
The loader also noted that the addition of a 2-inch mortar, with 36 smoke shells, added to his job. The mortar, adapted from the infantry’s 2-inch mortar, was fixed to fire the smoke shells ahead of the tank, allowing it to make its own smoke screen, independently of a Close Support tank. While this was an added burden, the crew testing the tank were unanimous in believing it was a worthwhile addition.
The second prototype Mark II was expected in the next few days. This differed primarily by moving the gun forward, easier to do because of the geared elevation system, so that the mantlet was external to the turret. Vickers hoped that by testing the two turrets against one another the preference would be worked out and adopted for production. Vickers own testing thought that the external mantlet provided a bit more room in the turret for the crew, and that it had the advantage of improving the protection for the crew. The second prototype was built without the cupola so that a straight comparison could be made by tank commanders, though it could be easily added if that was the recommendation of the trials. The turret hatch sizes had been increased by two extra inches over the previous version. One of the lessons from the fighting previously had been that crews found that hatches tended to be a little tight when trying to get out of a tank in a hurry.
The third and final prototype due at Lulworth was the Close Support version. In some ways this was the least changed turret, as the new 3-inch tank howitzer was designed to fit in the same space as the 2-pdr gun. The size of the 3-inch shells made it capable of carrying even less than the 6-pdr gun turret. There had been strong recommendations from the experience of 1st Armoured Division on the Somme that the Close Support tank should have an adequate supply of High Explosive shells as well as the more common smoke shells.
The experience of the 1st Armoured Division had also highlighted that the Close Support tanks tended to be used as the ‘rear-link’ tank. Even with the new Wireless Set No 19, that role would need to continue. Usually this was the role of the second in command of the Regiment in the HQ unit, and with the new radio, he would join its A-set to a wider network, and relay relevant messages to the commander on the B set. This would extend a squadron net to the regiment, or a regimental net to the wider brigade/division. Vickers had proposed a turret that would do away with the main gun altogether, just keeping a mock barrel on the front, but using the saved space of gun and ammunition, to have extra radios to allow better communications. They had also suggested that this might suit the Royal Artillery giving their Observation Post Officers a protected and mobile position to communicate with their batteries. Such a turret was ordered as a prototype, but wouldn’t be ready for another few weeks. When this had been suggested Vickers were asked about the possibility to provide an auxiliary power unit so that the radios could be used when the tank engine wasn't running. The Vickers team had various options to look at, and felt that it would be a relatively easy thing to do.
The thorough testing of the prototype Valiant Mark IIs would continue for some weeks, before a final decision was made on the final decision on which turret, or combination was to be put into production. Meanwhile Vickers continued to gear up for production of the 6-pdr gun for its tanks, while at the same time producing as many 2-pdrs as possible.
NB None of this happened OTL, but I thought it'd be easier to read if it wasn't in Italic.