Article on the 1950s Design Studies leading to the HMS Fearless LPD class

[TinWing]

This greatly expands on DK Brown's "Rebuilding the Royal Navy."

The Mariner’s Mirror 97:3 (August 2011), 177–200
‘Hit hard, move fast and sustain action’
The Replacement of the Royal Navy’s Amphibious Warfare Squadron and the Rationale for HMS Fearless and HMS Intrepid
Ian Speller
http://eprints.maynoothuniversity.ie/8844/1/IS-Hit-Hard.pdf

 

[Pirate Pete]

Excellent find Sir. As you say, fills in some of the gaps left by Brown.
Well done.

 

[The Skipper]

The dimensions & troop capacity of the DL/A do not seem to make sense. She is quoted as having a displacement of 11 500 tons, a waterline length of 500', a waterline beam of 82', a draught of 18' 3", a moulded depth of 44' (giving a freeboard of 25' 9"), and carrying 1080 troops plus 18 tanks, 8 self- propelled guns & 60 3- ton trucks.

Fearless & Intrepid had a similar length & beam, but a deeper draught of 21', a higher freeboard of 28', and could only carry 400 troops, 15 tanks & 27 vehicles, or alternatively, 700 troops & no vehicles. Fearless & Intrepid did have a larger ship's company, 580 as oposed to 385 on the DL/A, but I cannot see that would have made so great a difference in capacity.

 

[TomS]

My first question would be about additional non-vehicle cargo space in the two designs (the US differentiates between "square," vehicle parking area, and "cube," cargo volume). I'm not familiar enough with the Fearless design to know if there is additional cargo "cube' that the DL/A might not have that is not reflected in the tables. There may also be differences in how troop accommodation is figured. I believe Fearless' 400-troop figure was for long-term accommodation and she had a max capacity of 700 troops "hard-lying" (i.e. troops sleeping on the floors, in corridors, etc.) The DL/A troop figure may well be for short-term accommodation as well.

 

[The Skipper]

The capacity of the DL/A is given as 1080 troops PLUS 18 tanks, 8 self- propelled guns & 60 3- ton trucks, implying that she could carry them all at once.

 

[Hood]

Have you seen the diagrams of DL/A and DL/B as reproduced in Brown & Moore Rebuilding the Royal Navy?

The vehicle decks of the Fearless class extend to roughly the foremast. On DL/A the vehicle deck is longer, continuing past the superstructure to end about one quarter of the way down the forecastle. On the shorter DL/B, the vehicle deck also follows a similar layout, extending past the end of the superstructure above. Both vehicle decks more or less stopping where the hull width to allow two AFVs to park side-by-side stopped due to the hull contours.

A notional vehicle layout is shown for the vehicle deck on the sketches of both designs:
DL/A - 1 LCU, 3 LCM, 16 tanks, 8 SPGs, 10 3-ton lorries.
DL/B - 6 LCM, 13 tanks, 5 SPGs

It must be noted that, just like the LST designs of the same period (SL/A, SL/B, SL/C, BL/C, BL/D), that ramps were provided to the upper deck which doubled as a helicopter deck. Therefore the other 50 3-ton lorries on DL/A would probably be stowed on the helicopter deck.
The troop accommodation though is a mystery. Despite what the article says, presumably 1,080 must have been a maximum without vehicles as there is limited deck space and the superstructure is probably smaller than that of the Fearless class. Its worth noting that the US Thomaston class, on which these designs were based, only carried around 325 troops.

 

[The Skipper]

I have seen the diagram of DL/A, and I can see that the vehicle deck extends for most of the ship's length. I did not know, however, the length of the vehicle deck on Fearless & Intrepid.

 

[Yellow Palace]

I'm not sure Ian Speller's PhD thesis has been shared on here yet:

https://kclpure.kcl.ac.uk/portal/files/2925352/244039.pdf

The discussions around doctrine are extremely interesting, and the Mariner's Mirror article linked above seems to draw heavily on Chapter 6 of the thesis.

Interestingly, there were serious plans in the 1940s and early 1950s for one or more LSDs for the Royal Navy - the initial thought was to purchase the ex-Lend Lease HMS OCEANWAY from the US Navy, but building a new ship in British yards was thought to be cheaper and easier to sustain.

The requirement for the LSD was revived in the early 1950s. In 1952 staff requirements were issued for both a new LCM (LCM(8)) and a Landing Ship, Tank (Dock) (LST(D)). The function of the LST(D) was to transport and discharge in the assault 10 LCM(8) preloaded with 50 ton tanks, three American Landing Ship Utility (LSU), and as many stores as possible. The ship was to have a maximum speed of 17 knots and an endurance of 7,400 miles at 15 knots, fully loaded. In addition to crew, accommodation was required for 25 officers and 250 other ranks. The change in attitudes had been prompted by the decision that the Army might want to land individual tanks in LCM during the assault. The landing of first priority tanks in LCT had the disadvantage that it precluded dispersal, with four or five tanks in each craft. This made the loss of one craft at sea much more serious and raised the prospect of the lead tank in an LCT being immobilised on the bow ramp and blocking in the remaining vehicles. Also, the size of LCT(8) meant that they could not land in as shallow water as an LCM. Previous policy had been for individual tanks to land using the DD flotation system. The lack of DD equipment and the inability to launch DD equipped tanks from the existing ships and craft had led to this capability being allowed to lapse.

In his progress report of April 1952 CAW Thomas requested that the Admiralty proceed with the construction of a prototype LSD/LST(D) and LCM in 1953. According to the accelerated Fraser Plan for naval rearmament the LST(D) was not due to be laid down until 1956. By 1952 the Admiralty had given only preliminary consideration to the project. Thomas was anxious that construction of this vessel should go ahead and wrote to the Admiralty promoting the LSD as a valuable member of the fleet train due to its repair and maintenance facilities.Nevertheless, the LST(D)/LSD fell victim to the 1953-1955 defence cuts. In August 1952 the Admiralty reported that the project was in abeyance. In October 1953 CAW was still unsuccessfully pressing for construction of the LSD. It was recognised that without the LSD, tanks could only be landed in the assault given favourable beach and weather conditions. A contract to design an LCM(8) along the lines of the 1952 staff requirements had been issued to Vosper at Gosport. This design was completed in 1955. However, the cancellation of the LSD meant that there was no suitable ship available to carry the craft and the project was shelved.

Edit: footnotes removed for clarity