Data sent by CHARLES A. THOMPSON (519-1988) tells of battle damage to the RN aircraft carrier HMS ILLUSTRIOUS from aerial bombs over 10 through 19 January, 1941.

Basic Ship Data:

HMS ILLUSTRIOUS was one of three light aircraft carriers of a similar type built before World War II; laid down in 1937; launched in 1939 and commissioned in 1940.

Displacement (standard)........................................................23,000
Displacement (full load)........................................................27,000
Length............................................................................230 meters
Beam................................................................................29 meters
Draft...............................................................................7.3 meters
Flight deck length...........................................................229 meters
Armor (sides)....................................................................115mm
Armor (deck)...........................................................76 and 25mm
Speed.................................................................................30 knots
Machinery...........................................................three-shaft turbine
Power............................................................................110,000 hp
Fuel.....................................................................4,900 tons (prox.)
Radius of action...........................................................12,000 miles
Crew...............................................................................1,600 men
Aircraft........................................................................................72
Guns...............................sixteen 114mm twin dual-purpose mounts
AA guns..............................40mm in eight-barrel automatic mounts ..........................thirty-two 20mm automatic machine guns

Damage to Ship and Aftereffects

HMS ILLUSTRIOUS was enroute to Malta on 10 January, 1941 and suffered repeated attacks by German bombers throughout the day. The raid at 1239 by two formations of 35 to 40 planes was quite severe as aircraft dove down from 3,500 meters and dropped their bombs at altitudes of less than 400 meters - some as low as 25 meters! They leveled off at the very surface of the water. Armor-piercing bombs of 250 to 300 kilograms were used.

The ship received six direct hits; the flight deck was pierced. One of the crew, V. P. Kostenko, used handwritten materials at his disposal to write the description of this case where one explosion occurred on the hangar deck. The carrier was ablaze from stem to stern; the bridge structure was damaged; the electrical steering engine was out of commission but the ship was successful in using the steam-driven gear. Speed of HMS ILLUSTRIOUS dropped to 26 knots, but she still steamed for Malta.

During the next attack, which took place at 1604 hours, a bomb struck the stern section of the ship and two others exploded dead astern of ILLUSTRIOUS. Water, which mainly entered from sprinkler systems and fire hoses, flooded the hangar deck and wardroom. Obstructions in the nozzles of the hoses would not allow the water to flow out, thus the rupturing of the hoses themselves. The ship took a 5 degree starboard list.

Just as the ship entered port at Malta, the sixth and last attack began but no new hits were scored.

The fire in the hangar deck continued and the starboard list was increasing because the firefighting water did not drain out.

The difference in trim reached 1.5 meters and the bridge structure suffered from flooding. Four aircraft were destroyed by the fire, 14 were so badly damaged they were also worthless, and some of the ammunition exploded.

While at anchor in Malta for some days, the holes in the carrier were sealed, the water pumped out and the damaged sections were repaired. Between 16 January and 19 January, there were several additional air attacks and HMS ILLUSTRIOUS received additional damage, both above and below the water line from three direct hits of 500 kg bombs and one near miss explosion close alongside.

One bomb went through the flight deck in the bow section, penetrated down the portside, and exploded near the waterline which flooded several bow compartments.

Another bomb penetrated the flight deck, making a two-foot hole. The explosion took place over the hangar deck and as a result of the twisting of the deck, the aircraft elevators were damaged, and new fires broke out in the ship.

The third bomb exploded on the hangar deck and made a hole about 15 feet across.

On 19 January 1941, yet another underwater explosion caved in the armor belt 75mm and the outer plating below the underwater protection was dented 1,500mm. Outboard compartments flooded for a distance of 25 to 30 meters & the ship took on a 5 degree list. The brickwork of the boilers was shattered.

Conclusions

As a result of 8 to 10 direct hits by armor-piercing bombs and also from concussions from underwater explosions close aboard, HMS ILLUSTRIOUS suffered damage which led to loss of control and a partial loss of speed - and it was not possible to conduct air ops.

Direct bomb hits led to damage of the decks, aircraft elevators and other equipment and to the outbreak of fires which did not seem to hurt the fighting capacity of the ship.

Near miss underwater explosions in the water caused significant damage to underwater sections of the hull which led to flooding of some of the compartments and the ship took on a list & a trim difference. Part of the engines was put out of commission due to the shock. The ship's stability was seriously affected by the great quantities of fire-fighting water that collected on the upper decks.

The 76mm armor of the flight deck appeared to be inadequate to ward off serious damage, but it did contribute to localizing the damage from the bombs.

The underwater armor protection also played a critical part in limiting the amount of damage, and keeping flooding to a minimum. The actions of the crew played a most positive role.

KTB #113 will cover damage by bombs to the Royal Navy aircraft carrier HMS FORMIDABLE.