The Battlecruiser HMS Queen Mary

The HMS Queen Mary with deployed torpedo nets. Its structure of hundreds of chained rings can be seen in the close-up. Visualization 3D Stefan Dramiński

Queen Mary was also armed with torpedoes. Two single, submerged torpedo tubes were fitted on both sides of of the bow section, in front of the “A” tower barbette. Each of them carried seven torpedoes. The target’s data was transferred from a control post under an armoured cupola on the stern superstructure. The effectiveness of this weapon system was very limited and it was never used in combat. Lion and Princess Royal were the only battlecruisers to ever fire a torpedo during a battle.

Armour

The passive protection of Queen Mary was similar to that of her predecessors of the Lion class. According to the battlecruiser doctrine, the armour’s task was not a full protection against projectiles but to minimize damage caused by enemy fire. The priority was to limit the possibility of damage to crucial ship areas like engines, steering, main battery and command centres. The thickest armour was at the main waterline belt, the sides and front of the main artillery turrets and the barbettes. The poor armouring of the two decks contributed to the weak horizontal protection. The torpedo bulkhead was also too thin. Details are presented in the chart.

Propulsion

Queen Mary had two 19-metre engine rooms separated by a centre-line bulkhead. Each of them housed Parsons turbines driving two propellers on each side. The designed output of the turbines was 75,000 shaft horsepower although during trials, the ship achieved 83,000 shp. The turbine revolutions were transferred directly to the propeller shaft without a reduction gear. Queen Mary was the last battlecruiser with Parsons turbine of that type. Her successors were fitted with the more effective Brown-Curtis turbines or Parsons turbines with a reduction gear.
The condensers were located in a separate 15-metre room. The steam was supplied by 42 large-tube Yarrow boilers, six in each of seven boiler rooms. The10-metre-long No.1 boiler room with two rows of three boilers  was in the ship’s axis at the height of the foremast. Further towards the stern, the hull was beamier and the remaining six boiler rooms were placed in three pairs separated by the centre-line watertight bulkhead. Each room had three rows of two boilers (16 metres total). Four engine rooms were placed between the first and the second funnel, and the next two were behind the “Q” turret barbette. To protect the second and the third funnel against the blast from that turret, vertical metal deflectors were fitted on the deck.

Low aft deck. On the top – armoured fire control post, below it - “X” turret of the main battery, stern gangway and one of the propellers are visible. Visualization 3D Stefan Dramiński

 

Additional equipment

Lighting was provided by sixteen 24-inch searchlights mounted in pairs. Eight such sets were placed on the platforms of the forward and aft superstructures. On the deck there was plenty of space for communication boats. They were arranged as follows:
− two 32-foot cutters - on davits on both sides at the height of the first funnel
− two 32-foot cutters, a 30-foot cutter, two 27-foot whalers, two 30-foot gigs, a 16-foot dinghy and a balsa wood raft - on the platform between the first and the second funnel
− two 50-foot steam pinnaces, a 42-foot launch and a 36-foot pinnace - on the main deck in the area of the stern superstructure.
Three booms were used to lower the boats: the main one was fitted to the aft mast, the two smaller ones were placed symmetrically on the sides of the boat platform. Coal was loaded through numerous hatches on the main deck. It was performed with the help of four booms located in the area of the two aft funnels.
Like most of her contemporaries, Queen Mary was equipped with torpedo nets. Eighteen booms, fitted on each side, were used to lower a steel ring net. This barrier’s task was to set off the torpedoes in safe distance from the hull. While not deployed, the net was rolled up and placed along the edge of the deck and the booms were set up along the sides. Due to difficulties in handling the nets, they were dismantled from the ships’ decks, however Queen Mary retained hers till the end of her service.
The ship did not undergo many modifications. During docking in Portsmouth from January till February 1915, the foremast was shortened, replaced by a tripod and a main battery director platform was fitted. An observation platform was located on the stern superstructure, right behind the torpedo fire control centre.

Operational history

HMS Queen Mary was laid down, as the third Lion class battlecruiser, on 6 March 1911 at  Palmers Shipbuilding and Engineering Co. Ltd in Jarrow. Launching ceremony took place on 20 March 1912. The hull was moored at a fitting-out berth where armament, superstructures and masts were fitted and further construction work continued. John Brown’s factory in Clydebank supplied the propulsion system. In May 1913 Queen Mary was almost finished and ready for the first sea trials which lasted till August 1913. Meanwhile, on 1 July 1913, Captain William Reginald Hall became the first commanding officer of the ship. During trials conducted at the measured mile, Queen Mary achieved 28.17 knots at 83,003 shp.