One important and overlooked aspect of Mulberry was their use as breakwaters, protecting shipping unloading on the beaches from some of the more tidal forces.
Could they winch themselves off with their huge stern anchors? That was the plan but I've never seen them deployed. Have you?
Articles... I wondered how the investment in Mulberry compared with the axis spending on the "Atlantic Wall" - D-Day - Mulberry Artificial Harbours "I think it's the biggest waste of manpower and equipment that I have ever seen. I can unload a thousand LSTs at a time over the open beaches...What's the use of building them just to have them destroyed and litter up the beaches. Admiral John Leslie Hall, US Navy" And... D-Day - The Atlantic Wall "The whole Atlantic Wall project was a massive undertaking - and considered folly by many. It cost Germany an estimated 3.7 billion Deutschmarks and used 17 million cubic metres of concrete and 1.2 million tonnes of steel. Whilst formidable, the fortifications did not prevent the Allies from landing on D-Day, although well located firing positions were responsible for many of the British, American and Canadian losses in the first few days of fighting. Fixed fortifications are monuments to the stupidity of mankind. General George S. Patton, US Army" Economically the Nazi state made no sense.
No unfortunately not at Normandy, maybe in other landings. It is all to do with how steep the landing beach was. The Normandy beaches were relatively flat and an LST vehicle ramp only extended so far. Waterproofing vehicles only increased their ability to wade ashore so far. So an LST on a Normandy beach would run aground while the water was still too deep for vehicles to wade ashore. So the only solution was to wait for the tide to go out.The whole vessel was left high and dry on the beach, props and rudders out of the water. “Dried out” was the naval expression. Unloading an LST took time. Once the main vehicle deck was cleared everything had to be brought down from the upper deck. In the first 441 LST built this was done via an elevator/lift. In the later LST542 class a ramp from the upper deck replaced the lift but these only began to complete from early 1944 so were in a minority at Normandy. See here lst on the beach - Google Search They were then generally backloaded with casualties destined for hospitals in the U.K. or prisoners bound for POW camps where they wouldn’t be a burden on the front line troops to look after. So two tides a day = a 12 hour turnaround. That is why the LST pier at Mulberry B at Arromanches was such a boon. An LST pier had also been planned for Mulberry A but that was lost in the June storm. LSTs docking there could unload simultaneously from the tank deck AND the upper deck while still afloat. Here is a diagram of its layout lst pier at mulberry - Google Search lst pier at mulberry - Google Search lst pier at mulberry - Google Search Had the beaches in Normandy been steeper, then LSTs would have been able to remain afloat while unloading and might then have been able to winch themselves off using the stern kedge anchor. LCTs were also beached and allowed to dry out after the initial assault.
I would say that only part of the above is true and I don’t believe it’s contribution to eventual victory can be written off that easily. It was cutting edge technology for its time and was never expected to be the sole source of fuel for the Allied armies. Early on a terminal was put in place at Port-en-Bessin under code name Tombola, allowing tankers to discharge offshore into a pipeline and storage system (The Minor System). Later once Cherbourg was cleared another tanker discharge point was set up connected to a pipeline and storage system (The Major System) that eventually went all the way across the Rhine. This supply was augmented by tankers into other ports as they were captured. PLUTO wasn’t even a single pipeline type. It was two. Hais and Hamel with two different methods of laying and were eventually used in combination. PLUTO also covered 2 different pipe networks. The initial Bambi system to Cherbourg was a failure. Starting late, of 7 lines that were attempted to be laid only 2 could be brought into service on 22nd and 29th Sept. They failed on 3rd Oct. But the system had shown some promise and the personnel involved were on a learning curve. The second pipe network was Dumbo from Dungeness to Boulogne with the first lay being made on 10th Oct and the first fuel flowing on the 27th. By that time the Channel weather began to intervene to add to the delays in laying more pipes. Between then and 24th May 1945 a total of 17 pipelines were laid (6 by mid-Dec 1944). None of the 11 Hais pipes failed but the 6 Hais-Hamel pipes, while outliving their expected 6 week life, failed after between 55 and 112 days. The Dumbo system wasn’t shut down until July 1945. Capacity peaked around 4,500 tons per day (1.35m gallons per day) with 1m gallons per day being pumped for many weeks. Fuel losses were only 1.1% for the whole operation. To put it in the context of the massive amount of fuel used in the NWE campaign, some 5.2m tons of oil products were delivered through the ports of NWE. 826,000 tons (16%) came direct from the USA with the remainder delivered from Britain. Of that 370,000 tons (8% of the deliveries from Britain) was delivered via PLUTO pipelines. And that at a time when there was a shortage of tankers, particularly of the smaller coastal variety. So while I would agree that it played no part in the Normandy campaign, as the war had moved on beyond the Seine by the time it first came on line,I would not characterise it as something that “simply didn’t work”. Post-war propaganda may have somewhat exaggerated its contribution, but in the 11 month NWE campaign PLUTO delivered 8% of the total fuel requirements despite operating for only 7 months.
I’m not following you. AIUI the “resources” put into Chastity were minimal compared with to the development of Mulberry, PLUTO and the like. It was mostly planning and staff time, relatively little in material would have been needed to make it work. It began very late in the invasion process, only being signed off in April 1944 and was cancelled at the beginning of Sept. The D-Day planning did not foresee a German collapse and wholesale retreat across France or the capture of a port like Antwerp virtually intact. Had the Allies had to fight their way across France they would have needed every Biscay port they could lay their hands on. The beauty of Operation Chastity and Quiberon Bay was the lack of resources it needed to implement it. Some explanation of how it would have worked here. http://cgsc.contentdm.oclc.org/util...24201coll1/id/874/filename/875.pdf/mapsto/pdf
All the resources used on CHASTITY were 'wasted'. That is a fact only true in hindsight. Granted at the time is was a wise decision to have a plan to be able to ship direct from the USA to the French Atlantic ports. Events overtook CHASTITY and compared to a half-successful MULBERRY plan it was a 'waste' of resources-much like the CDL Regiments.
Has anyone got a reliable source for the assertion that the American's failed to anchor their Mulberry properly? I've often seen it mentioned but have never seen a reference to an official report/document.
not an official report, but... https://beckettrankine.com/wp-content/uploads/2019/01/kite-anchors-final.pdf pg. 17 perhaps also of interest http://www.southseasubaqua.org.uk/images/diving_projects/Mulberry70/20150627 Mulberry 70 report.pdf
Been doing a bit of digging and have found that Chester Wilmot makes mention of it in his book, 'Struggle for Europe' but provides no reliable reference. However, in one of Hartcup's books, 'Challenge of War' or 'Code Name Mulberry' (spun through both this evening with a couple of Pink Gins to hand) he mentions how British naval hands on Mulberry B recognised the signs of the incoming storm and began adding extra anchorage to various components which helped secure Mulberry B. He makes no mention of the American's doing the same at Mulberry A so the inference is that there was a difference in anchorage but not necessarily during the construction phase. Incidentally, Hartcup also mentions that the US Mulberry was probably salvageable but bias against it amongst some senior American commanders ensured it was written off, in spite of the fact that the US construction crew wanted to salvage and finish their harbour.
Reading through the material I have on Mulberry, including Hartcup, there seem to have been a number of factors that caused failures in either or both Mulberries during the June Storm, some of which were not forseeable, some of which represented calculated risks that didn't work out well, while others could heve been prevented by better implementation of the plan. Firstly it needs to be noted that neither Harbour was complete when the Storm struck. Mulberry A was is generally accepted to be in a more exposed position when the Storm struck and the ground on which it was placed was less suitable than that of Mulberry B. That said, the Mulberries were meant as temporary structures, with a lifespan of about 90 days in the likely conditions to be expected at that time of year. The June 1944 Storm has been described as a once in 40 year event that could not have been foreseen and for which the Mulberries were not designed. In a quick Google I came across this piece of research regarding estimated wave heights during the Storm. Significant wave height field from SWAN at the peak of the storm at... Most of the personnel responsible for their towing across the Channel and their erection lacked training to some degree or other in setting out the various units. So units ended up lost or damaged before arrival or were not always placed correctly e.g. Alynbank at Mulberry B. Hartcup notes that this was particularly so for the US personnel who didn't always apply the training they were given. He further notes for example "For this reason, on the far shore the Americans thought that the mooring of alternate spans would suffice, with the result when the bad weather came the anchors dragged and the bridge swung out of position. The British, on the contrary, doubled their moorings when the gale warning was given." US personnel, perhaps naturally, had less respect for European weather conditions and just how rapidly they could change. Hartcup cites conversations he had with some of the British officers responsible for the Mulberry project for his comments. In terms of changes to the plan, the Bombardons were supposed to be laid in a double line to seaward of the Phoenix Caissons and blockships. Instead they were laid in a single line and in 11-13 fathoms of water instead of the 7 fathoms for which their moorings had been designed. So they were much less effective and more easily destroyed. According to Hartcup, that was a decision by Admiral Ramsay but no explanation of the reasoning for that. The Phoenix Caissons of Mulberry B were placed in deeper water than originally intended to increase the harbour space. So their freeboard at high tide was reduced before adding in the effects of the storm waves. One or two of them and the blockships were not sunk in the right places. Due to the manner in which Phoenix Caissons were constructed (being largely open topped) and the method of controlling water inflow and outflow to their void spaces, once overtopped by heavy seas water could not escape, or escape fast enough, with the result that the internal pressure blew the sides out. Poor constuction by largely untrained labour probably did not help. The winterisation programme helped cure some of these problems. At Mulberry A, out of 31 Phoenix Caissons in place at the time of the Storm, 3 had their back broken due to scour around their bases and another 17 by having their sides burst open through water pressure. 7 of the blockships had their backs broken. Damage to the Mulberry B Phoenix Caissons was less extensive, but by looking at photos you can see where gaps were made by the subsequent extra units placed to seaward to plug them. Over at Mulberry A, that part of the breakwater made up of the Gooseberry of sunken blockships, was not continuous. To aid access to the Harbour the US decided to sink them so that 2x200ft gaps existed in it that allowed heavy seas through to damage the blockship line. As for the reason for not rebuilding Mulberry A, US bias against it undoubtedly played a part. But if you were standing on the beach surveying the extent of the damage in the aftermath of the Storm it must have been a very sorry sight indeed. Two thirds of the Phoenix wall destroyed, the blockship wall crumbling, pierheads and all sorts of surface craft piled up onshore. Anything can be repaired given enough time and effort. Those whose baby it is don't usually give up very easily. So I can understand why the decision to abandon it might be made even without the bias. The curious thing about the question of US bias is that come the planning for Operation Coronet in March 1946, US thoughts seem to have been reversed and they did turn to the production of an artificial harbour. Codenamed Ironhorse it was intended to handle as much cargo as both Mulberries combined. It would have seen blockships and steel/concrete Phoenix Caisson style breakwaters to withstand 20 ft waves, plus roadways and piers. All this to be constructed in the US and towed across the Pacific from San Francisco to the Tokyo area (5000 miles v 100 miles or so across the Channel to Normandy). In July 1945 this project held a production priority "above all military and naval programs except the Manhattan project". More about that can be read in "Hell to Pay. Operation Downfall and the Invasion of Japan 1945-1947" by D M Giangreco
My stoneage take on it it was worth it at the time with the knowledge and issues they had.A solution was required for a temp deep harbour "They were used to protect supply ships anchored off the coast of Normandy, north west France, after the D-Day landings of June 6, 1944. Supply ships needed to sit in deep water and so couldn't come in close to the shore. The harbours were intended to protect the ships from storms and enemy attack. The idea for floating harbours came from several people. Winston Churchill had suggested them as early as 1917." Mulberry harbours
The concept had been discussed previously in the Great War. Previous to this thread, there has been reference to the concept being raised by Hughes- Hallett in 1917 when a consideration was made to take the East Frisian Islands. When it came to the Second World War, Hughes- Hallett was said to have declared, if we cannot capture a port then let's us take a port with us. However in a nutshell, a landing could never have been made at a port which had the advantage of deep port facilities. Such a port would be heavily defended and to prepare it for invasion a heavy bombing programme would have had to effected which would result in the port sustaining serious damage from the air Then there was the aftermath, the Germans would demolish the port facilities as they did at Cherbourg. After the Dieppe operation, it was one lesson that the Allied planners learnt from this ill fated operation that an invasion through a port had distinct serious risks of failure. Even so to deceive the Germans there was the deception plan established that the Allies intended to launch the invasion through the Pas de Calais ports. Hitler believed it and always thought that the Normandy invasion was a deception and the main thrust would come at the Pas de Calais ports.
Cherbourg took several weeks to reopen because of the demolition. Brest was even more destroyed and did not reopen until after the war. I think General Middleton of US VIII Corps heading the assault, later wanted to call it off. He wanted just to bottle up the place, as they did elsewhere eventually, to save lives as it was now not worth taking the city. He was overruled.
