Barrow Built

V, N & G class, 1912 - 1921

Four of the class were ordered, the first being laid down in November 1912. The principal design feature was in the hull form. Although classed as double-hulled, the V boats were actually partial double-hulled vessels, the double-hull being limited to the middle portion of the boat, with the outer hull fairing into the pressure hull at the forward and after ends.

Vickers carried out a number of tank experiments on several hull forms before opting for this design. The estimated cost of the four V Class submarines was £76,100 each, but this was later amended to £75,799. The diesel engines of the V boats developed 450 bhp at 450 rev/mm and were the first Vickers-built submarine engines to have steel cylinder jackets - previously these had been of cast iron.

The battery consisted of 132 Exide cells - small for the size of boat: the A Class of less than half the displacement carried 120 cells. But the designed submerged speed was still attained, although at the expense of endurance.

V Class Submarines 1912 - 1919

Vickers claimed that the V Class could dive to 150 feet as against 100 feet in the conventional submarines of the period. Although the pressure hull sections were far from circular, this depth was possible because the strength of the hull was increased by the external framing between the inner and outer hulls.

The armament of the class was two 18-inch bow torpedo tubes, positioned low in the vessel. Two spare torpedoes, without warheads, were stowed on the starboard side of the torpedo room one above the other, with the warheads nearby on the flat. The torpedo hatch was mechanically operated as in the E Class. Some records state that a 12-pounder gun was fitted, presumably this was after completion.

All four V Class submarines were taken out of service in July 1919.

In December 1913, after discussing the German submarine programme, the Admiralty decided that they should prepare a design for an overseas patrol boat of about E Class surface displacement, of partial double-hull construction and with single 21-inch torpedo tubes forward and aft and two 18-inch beam tubes. This would be the G Class.

G Class Submarines 1914 -1921

In June 1914, five G Class submarines, G1 to G5, were ordered from Chatham Dockyard and one month later G6 and G7 were ordered from Armstrong Whitworth.

Vickers engines of the E Class type were fitted in all seven boats, although it was originally intended to fit G6 and G7 with Nuremberg (MAN) and Sultzer engines. (Difficulties obtaining the Sultzer engine and the impracticability of a MAN design prevented this.)

In November 1914, Vickers were given orders for six more boats, G8 to G13, and to build the engines for four of the class building at Chatham. G14 was ordered from Scotts on the Clyde.

Costing an estimated £125 000, the G Class were twin-shafted vessels, with two eight-cylinder diesels that together generated 1600 bhp, giving a surface speed of 14 knots. Two single armature motors, each of 420 bhp, gave a submerged speed of 9 knots. The class carried 200 cells in two battery tanks, which gave a submerged endurance of 95 miles at 3 knots.

Early war experience gained by other classes led to the proposed G Class armament being changed to two 18-inch bow tubes, two 18-inch beam tubes and one 21-inch stern tube. This signalled the beginning of the 21-inch torpedo in Royal Navy submarines, although the experimental submarine Swordfish ordered from Scotts a year earlier but launched after G1, was also fitted with 21-inch tubes. The class also carried one 3-inch Quick Fire High Angle (OF HA) gun which was fitted just forward of the bridge and a portable 2-pounder which could be fixed to a pedestal at the after end of the bridge.

Living conditions on board were considered by crew members to be good because the G boats boasted such luxuries as an electric oven!

Although the designed diving depth of the G Class was given as 200 feet, the operational depth was probably 100 feet. However, it was noted that in 'an exceptional circumstance one G boat dived to 170 feet when chased by mistake by British destroyers'.

During the First World War G7, G8 and G11 were lost on active service through unknown causes and in September 1917. G9 was sunk in error by HMS Petard off the Norwegian coast. Of those that survived, four were taken out of service at the end of the war and the remaining six were withdrawn from service in January 1921.

The Nautilus 1913 - 1919

Nautilus was a bold experiment - with an increase in surface displacement and a change from the saddle tank type of construction to a double-hull. She was a twin shaft vessel with two Vickers diesel engines, each of 1850 hp, two main motors of 500 bhp and 352 Exide cells in two battery tanks.

The Nautilus, renamed N1 in June 1917, was designed by Vickers to have good sea-keeping qual

ities for extended operations in all weather conditions.

Regarded by submarine officers as 'an exceedingly interesting experiment', Nautilus was laid down in March 1913 and, with an overall length of nearly 260 feet, was twice the size of any existing submarine.

The estimated cost of building Nautilus is given as £203,850 but, because of the extended building time, the changes that occurred, the increase in displacement and additions such as hydroplane guards, this figure was undoubtedly exceeded.

Although the designed surface speed is given as 17 knots, it is doubtful whether any reliable 'in service' figures for speed and endurance were obtained since she did not complete until October 1917 and had little, if any, service as an operational submarine. Her designed diving depth is given as 200 feet and compared with that achieved by previous classes this would seem to be reasonable.

Her armament consisted of two 18-inch bow torpedo tubes, four 18-inch beam tubes and two 18-inch stern tubes (with 16 torpedoes carried). A 3-inch High-Angle (HA) gun was fitted on the superstructure just forward of the bridge and this was raised and lowered on a vertical ram.

It is said that Nautilus was a failure. This may be true in that she had little real service experience, being used mainly as a Depot Ship for instructional purposes. However, Nautilus was significant because the step from small to large size submarines, with greatly increased engine power, had been taken, and this provided considerable experience and confidence for building later classes.

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