Amphibious operations

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US Amphibious Ships and Craft: An Illustrated Design History by Norman Friedman

Page 624

The British had actually considered converting merchant ships to carry tanks for a projected 1918 assault on Zeebrugge in Belgium. According to Lt. Comdr. The Hon. J. M. Kenworth, Sailors, Statesmen – And Others: An Autobiography, the Admiralty war staff proposed ‘to fit out old merchant ships too carry a dozen tanks each in their holds. The bows were to be reconstituted in such a way that they would run up on the beach in the known state of the tide….Slung up in the forepart of each vessel was to be a kind of drawbridge which would be lowered into the shallows and the tanks would trundle into the shallow water and ashore’. This proposal was ultimately rejected, but it was surely widely known within the war staff, and to the commander of the Zeebrugge attack, Adm. Sir Roger Keyes.


Anyone know if any designs were produced or was this just theoretical?
 
I know that there were various plans for an amphibious assault to the North of the Hindenburg line. This included and effort to use floating tanks in support of the 1917 Ypres offensive. This 1918 concept fascinates me and I would love to know more. However my knowledge of Allied planning in 1918 suggests that such an assault would not have happened until 1919. The great offensives (Allied) of 1918 were all rather ad-hoc affairs. I would love to know more about this and it may link in with some of the plans for Agincourt post war.
 
I have just remembered something, not specific to this case but certainly of interest:

In 'The Royal Navy 1930-2000: Innovation in defence'

There is mention that by 1926 there was a design for a Beach Motor Boat or Motor Landing Craft 1 that could carry troops, stores and guns ashore but not tanks. However by 1929 there was a design for a Motor Landing Craft 10 that he paragraph infers could at least carry a tankette or perhaps a light tank. Does anybody have any images or details of these two craft or any associated projects?
 
sealordlawrence said:
I know that there were various plans for an amphibious assault to the North of the Hindenburg line. This included and effort to use floating tanks in support of the 1917 Ypres offensive. This 1918 concept fascinates me and I would love to know more. However my knowledge of Allied planning in 1918 suggests that such an assault would not have happened until 1919. The great offensives (Allied) of 1918 were all rather ad-hoc affairs. I would love to know more about this and it may link in with some of the plans for Agincourt post war.

There was Operation Hush (not a Blackadder scenario as the name suggests.) which was to use bloody great 540ft long pontoons (later called Bacon Lighters after the Admiral who thought of them), lashed to Monitors. Three tanks to a pntoon which also had gear for clearing the sea wall.

http://www.ijnhonline.org/volume1_number1_Apr02/pdf_april02/pdf_page.pdf

http://www.1914-1918.net/hush.htm

But this description is of proper tank landing ships so doesn't seem to be anything like that.
 
the issue with Hush was the Sea Wall and getting the tanks over it, like you say this seems like a proper effort to land armoured forces. The real question, amongst others, is whether the plan was just a single raid or to be part of a wider offensive like Hush.
 
From ‘Amphibious Operations: The Projection of Sea Power Ashore’ by Colonel M.H.H. Evans - one of the Brassey’s Sea Power series of books

Admiral fisher contemplated the establishment of a flotilla of suitable craft for landings, but few were built. There was no support for a proposal in 1905 that the Royal Marines should form a force in readiness, trained to disembark rapidly on a hostile shore.


Does anyone know what were the craft that were built and what ideas did Fisher have on what was needed?
 
From John Terraine's 'Business in Great Waters'

'In September 1916, he (Sir Reginald Bacon) had been highly receptive to Haig's idea of 'special flat-bottomed boats for running ashore and landing a line of Tanks on the beach.'

Does anyone know what Bacon proposed, the use of the word 'boats' suggests something other than the pontoons that were built for Operation Hush.
 
From ’The Watery Maze’ by Bernard Fergusson

The LSD was the brain-foster-child of Hussey’s, who had introduced it to an initially sceptical world at a meeting in the Admiralty in September. He handed round a photograph of a ‘Popper’ barge transporter, such as was used on the Danube. These flooded like a floating dock, and while so flooded shipped a barge on either side of their superstructure; they then pumped the water out, so that the barges were lifted clear of the water resting on sponsons on either side of the ship. Such a vessel had several advantages. She would be designed to carry two loaded LCTs in a hold, or dock, instead of on external sponsons, as in the Popper barge.

Does anyone have any pictures of these Popper barge ships?
 
During the winter of 1941 the Admiralty Construction Department was working on a design for a mobile floating dock-ship that could take a single LCT on longer passages for possible raids beyond the LCT’s range. This requirement was outlined in September 1941 but the idea had been considered as far back as 1823 and noted in the transactions of the Institute of Naval Architects for a meeting in 1870. There were also Popper barges on the Danube which launched lighters from side decks when the barge flooded down. The Admiralty designs for this LSD were sent to America, where the Bureau of Ships and subsequently Gibbs & Cox of New York developed them for building in American yards.

Ladd, James D. Assault from the Sea 1939-1945 (p. 70). Lume Books. Kindle Edition.


Has anyone seen what was being thought of in the 1823 suggestion or what was noted in the the transactions of the Institute of Naval Architects for a meeting in 1870?
 
On a tangent:
 
Using this thread to ask a rather straightforward question. Why such a hodgepodge of old, converted carriers among the Iwo Jima LPH ? I mean, three Essex, one Casablanca and one Commencement bay - why ?

Were they looking for the "right formula" ? Between specialized-slow ships (Iwo Jimas), slow-old-small-carriers, and big-fast-Essex ? I don't get the point.






 
Using this thread to ask a rather straightforward question. Why such a hodgepodge of old, converted carriers among the Iwo Jima LPH ? I mean, three Essex, one Casablanca and one Commencement bay - why ?

Were they looking for the "right formula" ? Between specialized-slow ships (Iwo Jimas), slow-old-small-carriers, and big-fast-Essex ? I don't get the point.






Actaully cause at the time, 1950s, the USN couldn't afford to build specialize ones like the Iwo Jimas.

They had all those old ships sitting in mothballs doing nothing and so when they ask for money Congress basically ask why not use those.

Basically the old ships were there, basically brand new, and we were not doing anything with them so...
 
See Friedman “US Carriers. An Illustrated Design History”

USMC studies of helicopter assault dated back to a study ordered in 1946, but were slowed by the longer than expected time to develop the troop carrying helicopter.

FY52 & FY53 requests for new build helicopter carriers were turned down. The fall back was to be the CVE-105 Commencement Bay class but these were apparently needed for USMC support in Korea or ASW warfare. So attention turned to the CVE-55 Casablanca class. It was estimated 20 with HRS (S-55) helicopters, or 13 with HR2S (S-56) would be required to lift a USMC Division. Accommodating the later forced the remodelling of the aft flight deck and lift. Later the larger CVE-105 was brought back into consideration, but not until around the time that the last of these had left front line service in mid-1957.

But shortage of helicopters saw the initial request limited to 4 ships each capable of lifting 20xHRS, 850 troops and 75 tons of cargo. For FY55 4 became 2 became 1 ship. CVE-90 Thetis Bay was selected and emerged in July 1956 as CVHA-1 with 20xHRS helicopters and 38 officers and 900 troops. She was a very austere conversion and considered an experimental vessel. She was reclassified as LPH-6 on 28 May 1957 but in the meantime plans had moved on.

The second ship was then to be the larger CVE-106 Block Island and was the first designated as LPH. She was reclassified as LPH-1 in Dec 1957 and work began in Jan 1958 but was never completed. The reason being the scrapping of the CVE conversion programme in favour of new construction and the availability of a number of the larger straight deck Essex class dropping out of the attack carrier and ASW fleet.

The Iwo Jima LPH were by then then seen as the ideal, being less manpower intensive to run, with better berthing arrangements for the troops and better control facilities for USMC operations. But funding meant ships were ordered over a much longer period than intended. The 7 ships covered FY58, 59, 60, 62, 63, 65 & 66.

The Essex class conversions were seen as interim substitutes. The original 1957 plans, developed from March that year, would have seen half their machinery stripped out to generate more space for troops, vehicles and associated facilities. But money and their age meant a simpler plan was adopted aimed at cutting maintenance and running costs. So they lost guns and radars and had half their boilers mothballed so reducing their speed to 25 knots. 4 conversions were eventually planned - Boxer (reclassified LPH-4 30/1/59), Princeton (reclassified LPH-5 2/3/59), Valley Forge (reclassified LPH-8 1/7/61) and Lake Champlain. But from the numbering they clearly broke down into 2 ships in 1957 and a second pair in 1961. The last was dropped due to manning difficulties.

So it’s a tale of the USMC struggling to get the new build specialist ships it sought to modernise the amphibious fleet that was to support it. But forced to make do, there is a progression to steadily larger vessels better able to support the increasing size of the helicopters used by the USMC. So less of a “hotchpotch” than might at first appear.

There is one oddity however. There were more CVE-105 class available than might at first appear. The following were all mothballed by the end of 1947, with no further postwar service:-

CVE-105 Commencement Bay
CVE-109 Cape Gloucester
CVE-111 Vella Gulf
CVE-113 Puget Sound
CVE-117 Saidor
CVE-121 Rabaul
CVE-123 Tinian

The last two had gone straight to Reserve on completion without seeing service.

So it seems that these 7 were being retained just in case they were needed as ASW carriers.
 

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