Bombay is the western capital of India and in 1882 and at that time had the second largest population of all cities in the British Empire. It had one of the best harbours in India and was threatened by the French Naval Bases at Diego Suarez and Saigon. The harbour was protected by a number of batteries on the mainland as some fortified batteries.
In 1879 the defences of Bombay Harbour consisted of the following :
Two 10-inch RML guns
Two 10-inch RML guns
Three 7-inch RBL guns
Three 9-inch RML guns
Three 9-inch RML guns
Two 10-inch RML guns
Eight 9-inch RML guns
Two 7-inch RBL guns
Twelve 7-inch RBL guns
The simple plan on the right shows the layout of the various coastal defence batteries protecting Bombay Harbour about 1879. The majority of the armament is heavy RML guns, supported by some of the newly introduced 10-in BL guns.
At this time all the guns were mounted in open barbette batteries. Support was provided by two harbour defence vessels, each of which carried four 10-inch RML guns. In 1879 the Indian Defence Committee recommended additional 12.5-inch RML guns and a new battery at Kumballa Hill.
As a result of this report , a Submarine Mining Establishment was formed for Bombay. In addition eight 12.5-inch RMLs were delivered from the United Kingdom. It is believed they were to be deployed at Kumballa HIll, Malabar Point and Colaba Point.
In March 1885 a further report was submitted by the Government of India for new armament, but this was amended by the War Office and also by the Defence Committee of India. The various recommendations were put hold because of fact finding mission by Lieut-Colonels Ellis and Baker to Bombay in March 1886. They completed their report on 3rd May 1886 with the recommendations as shown below. A plan to mount four 10-inch RML High Angle Fire guns at Colaba was held in abeyance.
Mahaluxmi Battery
One 12.5-inch RML gun
Two 10-inch RML guns
One 10-inch BL gun
Two 6-inch BL guns
Two 10-inch RML guns
Malabar Point Battery
One 12.5-inch RML gun
Two 10-inch RML guns
Two 7-inch RBL guns
One 10-inch BL gun
Two 6-inch BL guns
Two 10-inch RML guns
Colaba Point Battery
Two 12.5-inch RML
Two 10-inch RML guns
Two 10-inch BL
Two 6-inch BL
Two 10-inch RML guns
Oyster Rock
Two 12.5-inch RML gun
Two 10-inch RML guns
Two 7-inch RBL guns
Two 10-inch BL
Three 6-inch BL guns
Three 6-pdr Q.F.
Middle Ground
One 12.5-inch RML
One 9-inch RML guns
Two 10-inch BL
Two 6-inch BL guns
Three 6-pdr Q.F.
Cross Island
One 12.5-inch RML
Two 9-inch RML
Two 40-pdr RML guns
Two 12.5-inch RML
Two 6-inch BL guns
Two 6-pdr Q.F.
The mounting for all these gun emplacements were completed by February 1891.
The 10-inch and 6-inch BL guns outlined above were all on hydro-pneumatic carriages in pits. In respect of Mahaluxmi Battery and the 6-inch emplacements at Colaba, they were open pits. In all other cases the HP mounts were in circular pits.
The RML guns were all mounted en barbette with C-pivot racers.
Six Machine guns were provided for Oyster Rock and Middle Ground Batteries. The distribution is not know. The 0.4-inch Gardner MGs were on tripod stands, the 0.4-inch Nordenfeld MG on pack transport mountings and the 0.303 Maxim MG with parapet mountings.
Telephone communications were established between all of the batteries. There lookout positions at the Prongs and Kennery Lighthouses, connected b heavy submarine cables to the island batteries and underground wires between the land works.
At this time no position finding stations had been established. Range Finders (DRF) were installed at each of the batteries.
There was a single electric light at Oyster Rock and consideration was being given to additional lights.
The Submarine Mining Establishment at Bombay was operational by 1887 and based on Butcher’s Island. A miner and submarine mining launch are also available. The minefield is electro-contact with the test room at Middle Ground. The actual minefield was to be laid across the width of the deep water channel to east of Middle Ground Battery.
Butcher’s Island is now used as an oil terminal.
By 1880 Bombay had a limited number of Floating Defences to support the Coast Defence Batteries. They included the following vessels which had apparently been purchased by the Indian Government:
Coast Defence Ships (Breastwork Monitors)
These specialised vessels were built with the introduction of rifled guns and ironclad warships. They were like small battleships built to operate in shallow waters around the coast. They were ideal for riverine operations. The Coastal Defence Ships tended to have a higher speed than monitors and often carried secondary armaments. Bombay had two of these vessels, both Cerberus Class Coastal Defence Vessels. The first vessel in this class was used in Victoria, Australia and there are ongoing attempts to preserve what remains of it.( http://www.cerberus.com.au)
The Abyssinia
Built in 1870 with a displacement of 2,910 tons, 225 feet by 42 feet and a draught of 15 feet. She held 90 tons of coal, with a top speed of 9.6 knots. The armour on the vessel was:
Sides – 6 to 7 inches Breastworks – 7 to 8 inches Turrets – 8 to 10 inches Deck – 1.5 inches
The armament of Abyssinia was two turrets, each mounting two 8-inch BL guns. There were also two machine guns and electric searchlights.
The Magdala
The Magdala was also built in 1870 was slightly larger than the Abyssinia. Displacement was 3,340 tons, 225 feet by 45 feet with a draft of 15.5 feet. The Magdala had a coal capacity of 120 tons, and a maximum speed of 10.4 knots.
Sides – 4 to 8 inches Breastworks – 8 to 9 inches Turrets – 9 inches Deck – 1.5 inches
The armament of the Magdala was four 8-inch BL guns in two turrets. Four machine guns and electric searchlights provided close defence.
Sharpshooter Class Motor Torpedo Boats
Ther were two Sharpshooter Class Motor Torpedo Boats, both built in 1890, named Plassey and Assaye. With a displacement of 735 tons, 230 feet by 27 feet and draught of 8.3 feet. They had a top speed of 21 knots and carried 100 tons of coal. They had a crew of 80 men, which included five Marines. The armament consisted of two 4.7-inch Q.F. guns, four 3-pdr Q.F. guns and three Torpedo Tubes with eight torpedoes carried.
First Class Motor Torpedo Boats
There were also three first class 125 feet motor torpedo boats with a speed of over 19 knots. They had a crew of sixteen men. These small vessels could patrol coastal waters and had sufficient range for independent action. The three boats in Bombay were armed with two 3-pdr Hotchkiss Q.F. guns and two 1-inch Nordenfelt machine guns. A total of fifty-eight 125-Footer Class of Motor Torpedo Boat (MTB) were built between 1885 and 1886. The were typically armed with five 14-inch Torpedo tubes, one bow and two pairs of deck tubes. The 125-Footer Class of MTB was designed however to have variable armaments, and the two-barrel Nordenfelt was often replaced by the 0.45-inch machine gun or Maxims. The two 3-pdr QF guns could replace the pairs of deck torpedoes, which would appear to have been done for the three vessels in Bombay.
There was also armaments available for six merchant cruisers in Bombay but these were intended to protect commercial shipping on the trade routes.
