The two Frobisher class carriers started life as part of the
Captain D'Urville class armoured cruisers. After only five and
six months of work had been undertaken on the ships, they were
cancelled , as armoured cruisers, and redesigned as aircraft
carriers. The General Frobisher was designed and built as a
typical 'flat top' carrier, and was accepted for service in
1924. This was the same period as the Hermes and Hosho were
completed, but the Frobisher class having had work incorporated
from their armoured cruiser beginnings could not be classed as
'from the keel up' designs. So Hermes was the first design as a
true carrier and Hosho first commissioned.
.PNG)
While the Frobisher was already complete and running with the
Scouting Force trialling different methods for the use of the
new type of ship. The Kirk-by was still in the builders hands as
the Admiralty trials different types of flight deck
configurations. The Kirk-by had 20 foot sections of flight deck
made so that different angles from zero to 30 degrees could be
evaluated for both the rear and bow of the ship. It was found
that the aircraft that were used in the trial had no difficulty
taking off while the ship was heading into the wind at anything
from 20+ knots. Having the different angles did not make much
difference to the low powered biplane aircraft. The admiralty
would dust off these trial results 40 years later and apply them
to the more modern and larger CV's in the fleet. The Kirk-by's
deck was returned to the same configuration as the Frobisher and
the ship handed over to the Fleet in 1927.
(I thought about doing drawings for these trials, but, in the
end, it required a lot of work that I was not willing to do.)
.PNG)
The main refits to these ships were the continual upgrading of
the armament. The single 4.7" low angle guns are removed and
replaced with 4.5" dual purpose weapons. The single 4" AA are
removed and replaced with quad 2 pounder weapons. Last but not
least, the old 2 pounder singles are replaced with modern 20mm
Hispano-Suiza cannons. The aircraft are continually changed in
and out as the new aircraft come into service. The standard
complement is twelve torpedo bombers, eight dive bomber/scouts,
and ten/twelve fighters.
| Displacement | 17,500 tons standard, 22,500 tons full load | |
| Length | 662 ft | |
| Breadth | 76 ft (94 feet over sponsons) | |
| Draught | 27 ft | |
| Machinery | 4 shaft, steam turbines, 100,000shp | |
| Speed | 32 knots | |
| Range | 14,000 miles at 12 knots | |
| Armour | 3" side, 3" deck | |
| Armament | As completed 8 x 4.7" (8x1) 4 x 4" AA (4x1) 8 x 2pd AA (8x1) |
1939 10 x 4.5" DP (10x1) 32 x 2pd (2x8, 4x4) 20 x 20mm (20x1) |
| Aircraft | 34 | 32 depending on size and type |
| Complement | 810 | |
| Notes | Captain D'Urville - completed as armoured cruiser Captain Badygin - completed as armoured cruiser General Frobisher - General Kirk-by - |
|
Aircraft available on the Frobisher class carriers to 1941.
