THE 'SEEHUND' RECOVERY

it is out there somewhere under the sands of northern Holland between the tiny holiday resorts of Rock'em and F Montaigne's II after a long process of wartime research and development the small Z Hunt class u-boat entered war duty in May 1944 operated by two men and carrying two under slung torpedoes thus a hunt caused devastation in the last months of the war sinking over 100,000 tons of Allied shipping their small size only eleven point seven meters long and rapid evasive capability made them virtually undetectable by radar although effective the submarines were very vulnerable and few crew survived after Allied forces found and tracked her for several days this particular example was finally beached at F monde by her captain it has remained buried ever since due to recent beach construction work and increasing risks of earth tremors caused by oil exploration in the North Sea the Royal Netherlands Navy feared activation of the torpedoes warheads their advice was prompt and safe disposal Salvage major vest Miller was called in to assist based on first findings a preliminary salvage plan was made and presented to the mayor of Bergen and all authorities involved a press conference is held to inform the public about the work to be done representatives of the Royal Netherlands Navy and vase Muller explained the plan questions are asked as usual World War two items are hot issues they're smaller Salvage and two other specialized Dutch companies are contracted for the operation an area with a radius of 1,800 meters around the submarine is firstly closed off to the public even air traffic is reroute 'add special metal detection devices exactly locate the submarine and it's torpedoes in order to access the torpedoes safely the solvers firstly construct a 14 by 18 meter sheet pile excavation bit around the submarine the burial site can only be reached at low tide and when there is an easterly wind to hold the water away from the coast these conditions are rare along the Dutch coast to help bypass the problem of the weather a 150 meter long bridge is built from the high-water mark to the submarine burial site the solvers are conscious of the Navy specialists insistence on avoiding any major vibrations or physical shocks that may detonate the torpedoes sensors are fixed to the Buried submarine to monitor any shocks during the building of the sheet pile excavation pit the solvers have to work very close to the warheads with shocks to be avoided a special piece of equipment is used the so-called silent piledriver after sinking the sheet piles a special frame is installed to reinforce the structure Wednesday the 24th of April 2002 ver smaller salvaged prepares for removal of the sand by pumping in water and pumping out the sand slurry with its dredge pumps a part of the hull becomes visible now the reinforcement of the structure has to be finalized to ensure safe approach to the torpedoes working at two meters below sea level the welders complete the precisely dimensioned reinforcement framework the hull appears it is in bad condition much of it corroded away so before the torpedoes can be approached the submarine itself must be stabilized in the meantime the solvers finalize their work on the access structure today a naval architect will do an inspection to determine how the submarine should be stabilized prior to dismantling pumps keep the fit dry while the team goes to work gently the submarine is actually in two pieces there are other areas of concern heavy batteries containing lead and pressurized air bottles are also in a very weak condition but the weather insists on living by her own rules on the 26 of April after nearly five weeks of good workable conditions the weather suddenly deteriorates the wind increases to gale-force and the site has to be evacuated all people and equipment are moved to a safe place this is the notorious west coast of Holland salvors and seabirds naturally have different opinions of what constitutes good working conditions for four days the protective structure is exposed to mother nature's energy breakers up to five meters high make work impossible the solvers can but watch their work frustrated sheet piles driven deep into the sand now wave-like reads in the wind face Miller salvages done corn knave closely inspects the damage that's out lookaside less the Cavill thesis the southwesterly part has partially collapsed and the pit washed out nominated through was over but stars and or well the sheet piles have sort of been sucked down it's still in place but a solution will have to be found for follow-up crystalline of cell radical the pit itself is luckily reasonably intact water is flowing in and out this should still hold but it will take us a week or two before it's repaired as long as more of this weather does not stop us salvage is always a fight against the Ellen's vestige of the element of liar indeed the elements take-no-prisoners the storm completely destroys a part of the 12 millimeter thick sheet pile construction and the damaged hardware has to be removed the framework inside the excavation has collapsed and must be recovered by the divers inspection shows that some six meters of sand around the excavation has been washed away and the structure destabilized the solvers have repair work to do you know safer made the shape of the cathedral men depth is seven meters seventy here at the moment nearly 25 feet yesterday we had over eight meters between the top of the sheet pile and the sea bed before the northwesterly the top of the pile to the seabed was only four and a half meters so we lost between three and a half and four meters of sand over the weekend now the bulldozer is moving it back and it's proving effective repair works on the excavation continued days of 15 hours and more are no exception to complete the job fast you many sheet piles have to be replaced the special silent pilot technique used to sink them into the sand means no shocks of any kind will reach the torpedoes that are only a couple of metres from them but the wind turns into its favorite direction a westerly and sand erosion accelerates suppression at a rate of some 100 tons per hour now runs continuously to protect the site and the weather forecast is bad things will deteriorate further within 48 hours and the solvers are running out of time yet more manpower and equipment is mobilized thankfully the Dutch contractors have plenty of experience in moving Sun about the place finally on Sunday the 12th of May the pit structure repair work is completed and the Royal Navy demolition specialists can approach the torpedoes now it's cereal bottle every time you do this there's something special real special although this scene is a little worse than I expected while the condition of the torpedoes is still unknown it is clear how the elements have destroyed the Buried vessel corroded and full of sand the explosives experts will have to take every care work is by hand and with the help of water other kinds of munitions than torpedoes are found near the submarine from small-arms shell cases to an anti-tank mine with all the sand removal of the remains requires a heavy lift capability over time even fishing nets got entangled with the wreck sans supply is necessary right up until the last moment both torpedoes on our free final measurements take place prior to dismantling it is still staking to be open this is the detonator area and here is where the u-boats net cutters were at the front before side if these are moved then a detonator could go out Scott's you consume as you can see it's all in very poor condition though the brass still glistens that looks brand-new it's Thailand Billa with all the steel part is completely corroded and that makes explosion possible we will dissemble by loosening the four bolts and then remove the detonator from the warhead remotely you can see the warhead is copper and still looks good new stuff water is used to gently wash away the Sun from the sensitive locations preparations for dismantling the torpedoes are now complete so it's time for the solvers to leave the site to the explosive specialists revitol her an explosive smile adding by means of a special cutter on a torpedo body we've separated the detonator and the rest of the torpedo the head has moved forward slightly which means the detonator is secured and the torpedo can be removed will explode it at sea like a goober night lengthen we've done what we set out to do everything safe but it was a tough job hey my mom in the book is a walker think of all the detonators had rotted into the warhead on both sides and Fillmore Deadwood springs alive ganar but with a lot of care and effort we removed explosives and detonators we cut the torpedo on the starboard side loose but had to remove it with explosive cutters on the port side expert even with the provided animals now it's being carried off by a Zodiac to the diving vessel which will destroy it at sea every hosted the beta for our board we've just taken the torpedo heads on board we placed an explosive charge and will shortly sink it to a depth of around 15 or 20 meters and then exploded exploitative one more long day of work and the naval specialists finish their work no damage to the teams no dangers to the tourists it is now up to the solvers to recover the son divers first attach lifting gear everyda mountable piece has already been removed first the stern section is hoisted to safety it will require a deep clean according to historical data the operational weight of the Sehun was 12 tonnes this bow section filled with sand alone weighs some 15 tonnes the press and visitors understandably follow events closely the same wand is removed for research and possible reconstruction who knows it may one day be on show in a museum to tutor and enlighten future generations the salvers start to clean up the beach in time for the summer season the removal of the pit and restoration of the site to its original pristine state now commences in a couple of days time no one will see that anyone or anything special was ever here the tourists have little idea of the risky work put in on their behalf the work of the mayor and municipal authorities the police the bomb disposal specialists and salvers goes on as here generations after the world shattering events of the past their work is not over yet

Channel: Svitzer Global

Views: 914,432

Rating: 4.7302051 out of 5

Keywords: Seehund, recovery, two-man submarine, sub, submarine, German, Seal Class, Egmond Aan Zee (City/Town/Village), cofferdam, sunken, torpedoes, disarm

Id: OZLf-nW338s

Length: 21min 21sec (1281 seconds)

Published: Wed Mar 19 2014