On December 31 2012 the mobile drilling unit Kulluk, owned by Shell and managed by Noble Drilling, grounded on a beach on Sitkalidak Island, Alaska, with no injuries or loss of life. The event was investigated by the US Coast Guard and their report published in April 2014. Later the American Transport Safety Board also released a report, which was published on May 22 2015.
The Aiviq. Photo in the Public Domain.
THE VESSELS INVOLVED
The Kulluk was a unique conical mobile drilling unit built for Beaufort in 1979 by Mitsui and laid up for many years prior to purchase by Shell for Alaskan drilling operations. It was operated on behalf of the oil company by Noble Drilling. It was 265 feet (81 metres) in diameter. Its construction was such that it was resistant to ice, which extended its drilling season in the far North. The hull was continuous in the form of a cylinder, at the upper levels taking on a sort of saucer shape, with the moonpool and the associated drilling systems in the centre. It was not provided with any means of propulsion.
The Aiviq was a heavy duty anchor-handler built at the Edison Chouest yard of North American Shipbuilding and managed by Offshore Service Vessels, which appears to be a company operating some or all of the Edison Chouest vessels. It was about 100 metres (328 feet) long, had 21,000 bhp available, making it able to exert a bollard pull of a little over 200 tonnes.
The Guardsman was a traditional Gulf of Mexico tug, built in 1976 by McDermott, about 40 metres (131 feet) long. With 7200 bhp available and able to provide a bollard pull of about 75 tonnes. It was operated by Crowley Marine Services.
The Alert was a modern 40 metre tug with twin Z drives providing 150 tonnes bollard pull from 10,000 bhp. It was built by Dakota Creek Industries and was operated by the Crowley Marine Service.
The Nanuq was a traditional AHTS built in 2007 by North American Fabricators. It was about 80 metres (262 feet) long with 7000 bhp providing 90 tonnes bollard pull. It was owned by Nautical Ventures which appeared to be another ECO company.
The Alex Haley was what the Coastguard call an ‘Medium Endurance Cutter’ built in 1967 by Brooke Marine in Lowestoft. It had, surprisingly, a crew of 104 and its towing capabilities were limited to a ‘Towing Bit”.
PREAMBLE
It appears that Shell decided to move the Kulluk to Seattle because there was considerable work required to bring the unit up to spec for the 2013 drilling campaign. Additionally, although denied to start with by Shell management in Alaska, it was likely, had the rig been in Alaskan waters at the end of the year, that Shell would have been charged several million dollars in tax on the capital value of the unit.
It seems that a towing plan was developed for the operation, but not against any standards or procedures, and subsequently this plan was passed for review to the following Shell personnel: Alaska Operations Manager, Alaska Drilling Manager, Logistics Team Lead, Health Safety and Environmental Team Lead and Emergency Response Specialist and additionally the ORMI (Offshore Rig Movers International) Tow Master, and the Noble personnel, the Rig Manager, the Operations Manager - Alaska and the GL Noble Denton warranty surveyor. Final approvers included the Alaska Venture Operations Manager, Alaska Well Delivery Manager, Alaska Logistics Team Lead, Alaska HSE Team Lead and the Alaska Marine Manager. All approvers were included as plan reviewers.
The Alaska Venture Operations Manager was considered the final approval authority but he was on holiday at the time, and so final approval lay with a deputy who had never reviewed a tow plan within Shell, had not participated in any of the planning meetings, and had not received any related training or even guidance about the process.
The final tow plan approval was received on December 21 2012 which was the actual day of departure.
An aspect of the plan was that the route would proceed in a broadly Easterly direction maintaining a distance within 200 miles of the coast, so as to remain within helicopter range. This was as an alternative to a great circle route, which would have been shorter, and at a greater distance from the coast. The report details the possible weather for three possible routes and determined that it was likely to be pretty awful no matter which was chosen.
The plan apparently took into consideration the previous towing records, which involved the Aiviq, once from Seattle to Dutch Harbour, as sole towing vessel, but in June, and also considered the expected adverse weather in the Gulf of Alaska in winter. Although by now the reliability of the Aiviq was, to say the least, questionable, it is not known whether any of the plan reviewers were aware of this.
The December towing plan apparently relied on a previous plan discussed in the summer which had involved people from Shell, Noble Drilling, Edison Chouest, Delmar Systems, Offshore Rig Movers International and MatthewsDaniel. And the report says that there was no evidence of any reassessment of the towing configuration, This, even though the Kulluk required 200 tons of bollard pull to hold it stationary in specific adverse conditions – which were likely to be met during this operation.
Because of subsequent events much space in the report is devoted to the change in the Kulluk towing configuration prior to its departure from Seattle in July 2012. This involved the substitution of the three 85 ton SWL shackles used in the monkey’s face (towing plate) connections with 120 ton SWL shackles,. The concern to the investigators was the lack of information on the source and certification of these shackles, although it was not suggested that they were unsuitable. It seems that they just happened to be in store in the shipyard.
There were also changes to the length of the 76mm pennant used as what we have come to know in Europe and the ‘weak link’ although it is not identified as such in the report. This was lengthened from 40 feet to 100 feet to reduce the difficulties of connection. The ‘emergency tow wire’ was also not quite as specified, now including a 400 foot length of ‘Samson Saturn’ rope and the substitution of three 120 ton SWL shackles for 85 ton shackles – but one 85 ton shackle remained in this system. It was also provided with a significantly shorter chain. If nothing else the failure to reflect these changes in the actual plan shows a lack of attention to detail.
The report goes on to consider the readiness of the Aiviq for the tow, and was able to identify many minor and fairly major failings in the ship’s equipment. These were stated in the report to be ‘a host of mechanical problems’. However the most serious item highlighted by the master was that the ship was consistently taking water on the main deck, the main deck safe areas and in the winch space in adverse weather, in one case resulting in the vessel taking on a ‘sustained list’.
On December 19 the GL Noble Denton warranty surveyor inspected the Aiviq and noted no deficiencies in the vessel. He also inspected the Kulluk and its towing arrangements, failing to notice that the 85 ton SWL shackles for which the rig held certificates had been replaced by 120 ton SWL shackles. The surveyor was present as the towing system was made up on the quayside, and related photographs are contained in the report. But the make-up did not result in any changes to the shackle connecting the towing plate to the weak link which had been in the same position since being fitted in Seattle.
THE SEQUENCE OF EVENTS
December 21 2012.
1430. Kulluk under tow of Aiviq departs Captains Bay bound for Seattle.
1600. Tow reaches open water and the tow line is extended to 1700 feet (518 metres).
December 22 2012.
The Kulluk towmaster and the Aiviq master discuss the possibility of changing to a great circle, but the Kulluk is keen to keep within the range of SAR helicopters, and so the prepared route is maintained.
December 25 2012.
Aiviq No 2 main diesel engine develops an oil leak requiring monitoring and on occasion the shut down of the unit. The master appraises Edison Chouest, the towmaster and Shell of the situation.
On this day further discussion about routing takes place and the possibility of taking a more southerly route to avoid an approaching low pressure system is considered.
December 27 2012.
Morning. Wind SE 20-25 knots. Aiviq’s winch control starts generating high tension alarms. More wire is paid out and apparently the vessel slowed, although later investigation was unable to determine that this took place. A video taken by one of the watchkeepers at about 0900 shows the tension in the tow wire cycling between 35 tons and 228 tons.
1135. The tow is lost, apparently due to the failure of the 120 ton shackle connecting the tow line (actually the weak link) to the towing plate. The Kulluk is adrift 52 miles from Sitkinak Island. The Kulluk recovers the towing plate and the Aiviq recovers its tow wire. There is no sign of the shackle. The tug Guardsman and the Nanuq (An AHTS but designated as an oil spill response vessel) are notified to get under way. The Coast Guard vessel Alex Haley is instructed to proceed to assist.
1200+. It is decided to reconnect the tow using the emergency system, since the use of the Kulluk cranes in the adverse weather is deemed to be inadvisable. Aiviq approaching to pick up emergency tow line, takes a roll and its J-Hook breaks loose and requires restowing.
1445. Aiviq successfully reconnects to the emergency tow line, and the Kulluk is towed away from an eight fathom patch, considered a danger due to the rig’s draught of “10.7 metres”.
2255. The Aiviq’s No 2 diesel is shut down for oil level checks and refuses to restart, and soon afterwards the engineers note that the injectors are failing on all engines.
December 28 2012.
0131. Wind SW 25-30 knots. The Coast Guard cutter Alex Haley arrives on scene.
0245. All the main engines have shut down, so the Aiviq is propelled by the 2600 bhp azimuthing thruster and directed by the tunnel thrusters, provided with power by the ship service generators. The ship is able to maintain station ahead of the tow but all are being pulled astern.
Subsequent to the loss of the main engines it is agreed between the masters that the Alex Haley will try to take the Aiviq (and therefore also the Kulluk) in tow. This process involves the firing of a line to the Aiviq. The crew on the bow of the anchor-handler then attempt to recover a thicker messenger which is connected to the Alex Haley towing hawser. The Coast Guard vessel has problems maintaining station and the crew mistakenly think that the process is more advanced than it is. They deploy the towing hawser too early, and this results in 800 feet (245 metres) of messenger line and part of the towing hawser being picked up by the Coast Guard ship’s port propeller. The attempt to connect up is abandoned.
0600. 5 injectors are replaced on Aiviq’s No 1 main diesel and it is successfully restarted. However the ship and tow are still being pulled astern.
1115. Alex Haley is instructed to depart for Kodiak for repairs.
1329. Tug Guardsman arrives on the scene.
1538. The Guardsman has the Aiviq and therefore the Kulluk in tow. But the whole set is still being pulled slowly astern. The Guardsman’s towing system is of course commensurate with its available bollard pull.
Late evening. The Kulluk lowers its emergency anchor to a depth below the hull. The ships and the tow are now about nine miles from the island. This emergency anchor is a 15 ton LWT connected to 900 feet (274 metres) of chain. There is much in the report about the timing and intent of the anchor deployment, but the reality is that it seems to have done no good.
2300. Wind SE 35-45 knots. Helicopters arrive on scene to attempt to evacuate the Kulluk, but due to the pitch and heave of the unit and the proximity of the derrick the attempt is abandoned. At this time the Guardsman reports that they are still being set towards Sitkinak Island.
December 29 2012
0300-1000. 74 new injectors are delivered to the Aiviq in 12 lifts by Coast Guard helicopters.
0425. Tug Alert departs from Port Etches near Valdez for the location.
0510. The Guardsman’s tow wire parts. Subsequent to this the Kulluk’s emergency anchor is deployed again and drags over the seabed without holding.
0630. Nanuq arrives on scene, and after daylight prepares to take the Kulluk in tow, connecting to the rig by using a line throwing apparatus.
1150. Nanuq has the rig under tow using No 8 anchor wire connected to its 64 mm tow wire. Aiviq is still towing the rig, with its azimuthing thruster, on the emergency tow line.
1200. The Kulluk’s emergency anchor is recovered and the tow begins to make progress away from Sitkinak island.
1235. The evacuation of the 18 crew of the Kulluk by Coast Guard helicopter commences.
1335. Evacuation of the rig is completed. Hence no further changes to the towing configuration are possible with intervention from the riding crew, and command on scene transferred from the towmaster to the master of the Aiviq. All the Aiviq main engines are now back on line. While those in the “Unified Command Centre” ashore might now be breathing a sigh of relief, the operation is now threatened by worsening weather.
December 30 2012.
Morning. Wind SSW, 40-50 knots.
1315. Nanuq’s tow parts, and shortly thereafter the Aiviq tow parts at the spliced eye of the emergency tow line. The Kulluk is now adrift approximately 30 miles from land.
1325. Tug Alert arrives at the scene, but initially is unable to connect to anything due to the clutter in the sea in the vicinity of the rig.
1630. It is decided that the Aiviq will grapple for the No 8 anchor wire, now trailing on the seabed astern of the drifting rig, together with part of the Nanuq’s tow wire.
1915. The Aiviq departs to sheltered waters to rig its grappling equipment – probably a grapnel (named in the report as a grapple anchor).
December 31 2012.
0031. Aiviq, with the grapnel over the stern, departs sheltered water for the rig.
0110. Alert successfully connects to the emergency tow line by recovering the end to the deck and putting a bowline in it, then connecting it to their own towing gear. It starts to tow the rig away from the shore.
0357. The Aiviq is back on the location.
0445. The Aiviq successfully grapples the No 8 anchor wire. There is no sign of the Nanuq’s tow wire, or the connecting 150 ton SWL shackle.
0510. Aiviq and Alert now have the Kulluk under tow. They are proceeding towards Port Hobron a safe harbour on the Northeast side of Sitkalidak Island on instruction from the Unified Command. This requires a tow of approximately 74 miles.
1131. The Guardsman is released from the area with gearbox problems.
1336. Wind ESE 50+ knots. A four person salvage team is lowered onto the rig from a Coast Guard helicopter.
1448. Salvage team is recovered to the helicopter due to worsening weather.
1530-1600. The master of the Alert reports that he has been required to take evading action several times to avoid collision with the Aiviq.
1600. The Kulluk begins to pull both vessels backwards towards Sitkalidak Island and so they increase power.
1624. Wind SE 40-50 knots. The Aiviq’s tow parts at the 76mm weak link. The Alert is now being pulled astern by the rig. By now the tug is attempting to influence where the rig will go aground. The Aiviq master considers that there are no other possible means by which the tow can be reconnected.
1815. The Alert master orders 100% power to influence the speed of drift of the Kulluk, but due to engine alarms has to reduce power to 85%.
2010. The Alert releases the tow with the Kulluk 3 miles from the shore on instruction from the Unified Command, by spooling the tow wire off its drum..
2040. The Kulluk grounds on a stretch of shoreline near Oceans Bay, Sitkalidak Island.
THE US COAST GUARD INVESTIGATION
The investigators considered numerous points regarding the incident, many of them concerned with the bollard pull required for the tow which, based on studies carried out over some years before the event, would be 200 tons according to the tow plan. However those who planned the move from the beach onwards calculated that the required bollard pull would be 282 tons.
Additionally while those engaged in towing in the Gulf of Alaska were accustomed to allowing themselves to be pulled astern in adverse weather, the routing of the Kulluk to did not allow for this option.
The towing gear on the rig also came in for some criticism, since it had not been specifically assessed in relation to the December tow. The GL Noble Denton warranty surveyor did not assess the towing arrangements despite the fact that the contract between GL Noble Denton and Shell stated that the former was hired “to provide warranty survey and certificate of approval for the tow”.
Of course the 120 ton SWL shackle which was the source of the original loss of tow came in for considerable investigation without any real result, other than the fact that it seemed to be what it purported to be. All the shackles and sample new shackles of the same make were tested to destruction after the event and it was concluded that the cyclic loading might have caused fatigue. A further section in the report compares the shackles provided with the possible requirements determined for this type of tow in the “US Navy Towing Manual”, and as might be expected they were found to be less than adequate, although one might note that the 85 ton SWL shackle which remained in the emergency towing system did not fail.
The report considers that the watchkeepers did not take appropriate action to reduce the shock loading on the tow. On the other hand the company had not provided any guidance for towing, nor had the Captain of the Aiviq issued any specific instructions about conducting the tow.
There is a review of the competence of the ship’s deck officers, none of whom had worked in Alaskan waters during the winter. The watchkeepers were divided into two groups each consisting one a regular mate and a 3rd Mate “Anchor Captain” . Each group worked for 12 hours at a stretch (Illegal apparently in US ships on ocean voyages of more than 600 miles) with the Captain being on call. The report concludes that the watchkeepers did not take appropriate action to reduce the fluctuations in tension in the towing system on December 27th. Analysis carried out by Rolls Royce after the event determined that the overload alarm described as “wire tensile strength overload on tow drum” occurred on 38 separate occasions. It would seem that the alarm would have been triggered had the load on the wire exceeded 300 tons. The watchkeepers had no recollection of receiving these alarms.
The Aiviq’s general condition came in for investigation and it was found that there had been an complete blackout and an engine failure while towing on a previous occasion, and that some modifications were recommended by the ship’s crew mainly dealing with the ingress of water onto the working deck, into the winch houses and into the safe areas. Specifically it was requested that doors for the safe deck area be installed and that the tank vents be extended upwards, but none of this work had been done prior to the departure of the tow for Seattle. Some of the previous failures were required by law to be reported to the Coast Guard but this had not been done.
After the casualty an engineering investigation was carried out and it was determined that probably the fuel injectors had been degraded over time and that therefore it was probable that there had been water in the fuel in the past. A petroleum test by DNV determined that there was 0.5% fuel in the port day tank, and the engine manufacturers specified a maximum water content of 0.05%.
The report contains a detailed description of the fuel system, which is provided with four vents terminating 30” above main deck level. These vents allowed water from the main deck to enter the overflow tank and to quote the report “The circuit breaker for the fuel oil overflow tank alarm had been secured for unexplained reasons some time after midnight on December 26th”. Once the overflow tank was full it was possible for all tanks to be contaminated, including the day tanks. The Chief Engineer did not apparently realize this, even though his maintenance report suggested that the deck vents needed fixing.
Also the ship was provided with a DPII system and the FMEA for it had required that each engine be supplied with fuel from a different day tank. The configuration used was to provide fuel for two engines from one tank and two from another.
The report goes on to discuss the weather at some length. Well, what the people planning the tow should have read was the short statement about the weather in the Alaska Pilot book. It is contained in the report and is reproduced here:
“The Aleutian Low looms over the North Pacific as a climatic warning to mariners navigating the Alaskan waters. This semi-permanent feature is made up of the day-to-day storms that traverse these seas in a seemingly endless procession. With these storms come rain, sleet, snow, the howling winds and the mountainous seas that make the northern Gulf of Alaska and the southern Bering Sea among the most treacherous winter waters in the Northern Hemisphere.”
Also considered were the limitations of the vessels called to support the emergency and then the report goes into conclusions most of which can be gathered from the summary of the recommendations which follows.
Several of the recommendations determined that the Coast Guard should have a greater oversight of towing activities, both in Alaskan waters and generally. They also suggested that Shell should do better in terms of policies, procedures and criteria for towing operations, and that Edison Chouest should put in place towing procedures as part of its safety management system, and develop training processes for masters and mates They suggest finally that the engineering deficiencies of the Aiviq should be fixed.
Unusually the investigators commended almost everyone actively involved in the accident, mostly for their skill and resourcefulness.
THE NATIONAL TRANSPORT SAFETY BOARD REPORT
At the outset it appears that the investigation carried out by the NTSB was of a slightly different catalogue of misfortunes than that carried out by the US Coast Guard, although the final outcome, the Kulluk aground on a sandy beach was the same. It may be that this was the result of personnel being interviewed a long time after the event, if the publication date is in any way related to timing of the investigation.
Apparently the Warranty Surveyor from Noble Denton had checked out the Aiviq and had interviewed the Chief Engineer who had been asked whether there were any engineering issues, to which the Chief had answered that there were none. The report noted that the Warranty Surveyor had inspected the towing gear on the day of departure, and it also discussed the lack of any formal regulation or requirement for towing equipment, although the towmaster had suggested that the industry standard is five years for towing systems.
The timing of the misfortune is described in the NTSB report and it seemed that the team who had dispatched the Guardsman and the Nanuq had also located and contracted the Alert on December 27, the day of the first loss of tow, although the Coast Guard report states that it did not depart from Port Etches until the morning of the December 29. It may be that the recollections of those involved in the incident had become a little more supportive of their actions over time. Apparently the towmaster also advised the Aiviq that once the emergency towing gear had been connected the tension on it should not exceed 60 tons.
The Edison Chouest response to this had been that once all the main engines had failed, the azimuthing thruster of the Aiviq could provide a bollard pull exceeding this figure. (The azimuthing thruster specification indicated that it had 2600 bhp available, and such power would usually offer a bollard pull of about 30 tons.) Later the same emergency towing system was seen to be capable of supporting a bollard pull close to 150 tons, exerted by the Alert, so one assumes that the towmaster’s instruction which seemed to support the limited emergency capabilities of the Aiviq, was incorrect.
Later the Edison Chouest team were to suggest that the reason for the fuel injector failures were due to contaminated fuel loaded in Dutch Harbour, rather than the entry of seawater into the system, as identified by the Coast Guard investigators. The NTSB decided that the source of the contamination was outwith the scope of their investigation, although readers might wonder why they were unable to accept the conclusions of the investigation into the Aiviq fuel system by the “Marine Safety Centre”, which is included in the Coast Guard report as a 20 page appendix. The only statement in this investigation which supports the ECO view is the fact that the Chief Engineer used one of the day tanks for storage, loading fuel from the shore directly into it!
The report then referenced studies into the decision making process where “multiple entities” are involved, and one of the them favours a particular outcome, and was able to point the finger at Shell, as the designer of the plan, the main reviewer of the plan and the one with the greatest interest in its approval without modification. The cause was, in the opinion of the NTSB, Shell’s inadequate assessment of the risk for the tow. Indeed, one cannot argue with the fact that the provision of a second towing vessel would have made all the difference, even allowing for the unreliability of the Aiviq.
COMMENT
For some reason the timings in the executive summary of the Coast Guard report are not the same as those in the main body of the document. Also all names have been redacted, except for the name of the investigator and the Coast Guard Rear-Admirals.
It is likely that the multiple reviewers of the towing plan were relying on some-one else to identify the shortcomings, if there were any, and were probably unaware that the Aiviq was deficient in a number of respects. But there is no doubt that some-one should have checked out the weather, the required bollard pull, the available bollard pull and the towing systems. And here we should remember that the towing plan still showed 85 ton shackles in the system.
It is possible that at least some of the problems related to the manner in which the Aiviq was being operated. It appears from the photographs in the report, and virtually all photographs on the internet that the ship’s roller is partially submerged at all times, giving a freeboard of maybe three feet (1 metre). This situation has not been commented on, so it is not known whether it is a requirement to maintain stability or Gulf of Mexico custom and practice, continued in error. On a ship of these vast dimensions a freeboard of maybe 10 feet (3 metres) should be possible, if no underdeck drilling supplies are being carried. More freeboard would have resulted in less, or no, water in the fuel (if the Coast Guard findings are accepted).
The towing equipment got a lot of space in the report, particularly after the loss of the 120 ton shackle from the towing plate. This resulted in the weak link, which is only included so that it will break if the system is stressed and the rig can then recover the towing bridle, becoming part of the Aiviq’s system and it remained part of it even when it was no longer required. There is a lot of stuff about percentages of proof load for shackles included in towing systems, but this may only be because large shackles are sometimes too big to go through the eyes of Telurit splices, and therefore the wires should be differently terminated or else Baldt or Kenter links used. We were not told how the Aiviq’s wire was terminated, but the weak link was fitted with a Spelter socket. As far as shackles go, surely it is the bigger the better, or even better, use a Kenter link.
After the first loss of the tow everything else was a contingency measure. Some of these measures worked quite well, and some were ineffective.
The emergency towing system worked pretty well, despite the towmaster’s apparent reservations. The Aiviq managed to pick it up and connect up, and it was only the failure of the main engines which then gave major problems. It might then have been fortunate that the thrusters, including the 2600 bhp azimuthing thruster were powered by the service generators.
The Guardsman did quite a bit to stabilize the situation, considering the age and dimensions of the vessel, and the Nanuq also did a pretty good job within its capabilities, and for a while things seemed to be going well. Was it a good idea for the onshore team to instruct the vessels to take the rig to the nearest safe harbour? It is difficult to tell. Instinct would suggest that the primary objective should have been to gain more sea room, but if the weather was never going to get any better would there have been any point? But looking at the weather charts included in the report there might have been an opportunity to gain sea room on December 28 but the tow was not re-established until December 29.
When the Alert joined the fray it was like the arrival of the cavalry in a 1950s western. It bustled about and got on with the job, and there is every chance that if the guys on the Aiviq had removed the weak link from their towing system, the situation would have been saved. Some might say that it is easy to pontificate about this in hindsight, and it is, but the point is that many opportunities to prevent the problem from occurring at all were presented but ignored, and in addition quite a few opportunities for recovery were also presented, but due to poor advice or lack of equipment these were missed. And it is noted that the management on shore claimed to have contracted the Alert at the same time as they sent out the Guardsman and the Nanuq (NTSB report), so why did they not dispatch it immediately rather than waiting for two days?
These questions lead to consideration of the make-up of the Shell Incident Management Team, whose first actions according to the report were to locate possible assistance towing vessels, hence it was they who sent out the Guardsman and the Nanuq. This was not too much of a stretch, since both vessels were on hire to the company. On December 28 the Shell team was enhanced to become a Unified Command structure, according to the report to “co-ordinate vessel response and potential oil recovery operations”. This group apparently consisted of representation from Coast Guard, Shell, Edison Chouest, Noble Drilling, State of Alaska and Kodiak Borough. Was there a towing expert amongst this large group? Who knows.
The Kulluk was in the end too badly damaged for it to continue to be useful, and it had proved itself to be difficult to move from place to place, and so it was loaded onto a heavy lift ship and taken to the Far East to be scrapped.