ANNEX D

SALVAGE STRATEGY AND EXECUTION - PERIOD 1

General

D.1.1   Period 1 covers the time from 2007 hrs on Thursday 15 February to 1300 hrs on Friday 16 February.

During this time the wind was westerly force 5 with moderate sea and swell.

These wind conditions were reasonably well predicted. The forecasts issued at 2028 hrs on Thursday 15 February and 0844 hrs on Friday 16 February predicted the wind to be from west-by-north force 3/4 at first, increasing to force 4/5 later from between west and northwest-by-west.

The 0844 hrs extended forecast predicted that the wind would remain at force 4/5 from the west that night but would increase to between force 4 and 6 from the west-southwest during Saturday and increase further to force 7 by 2400 hrs. (The Beaufort Wind Scale giving mean wind speed equivalents is at Annex E.)

Predicted low water at Milford Haven on Thursday was at 2139 hrs, with high water at 0342 hrs on Friday and low water at 1011 hrs.

Sunrise was at 0732 hrs on Friday.

Narrative and Discussion - Immediate Grounding

D.1.2   At about 2007 hrs SEA EMPRESS grounded on the western edge of the Middle Channel Rocks. As soon as it was realised what had happened, the pilot requested the immediate assistance of the tugs (which were waiting to berth the vessel). He used VHF Channel 12, because he knew that the tugs would be listening on that Channel. In the meantime, although her engines were stopped and then put astern and both anchors were dropped, SEA EMPRESS still made headway until grounding again 3.3 cables south-by-west of the Mill Bay Buoy, on a final heading of about northwest (see Figure 2 Image 92k).

D.1.3   When the tugs arrived at 2018 hrs the casualty was aground, trimmed down by the head, listing to starboard with the main deck in way of the shoulder at sea level. The tug DALEGARTH (45 tbp) made fast to the casualty through the forward centre lead, with the tug THORNGARTH (45 tbp) on the port bow, both tugs using their bow lines. The tugs STACKGARTH (43 tbp) and TITO NERI (50 tbp) were stationed on each quarter of the casualty ready to evacuate the crew however this was not considered necessary.

D.1.4   Within 20 minutes of the initial incident the casualty had listed to about 18° to starboard, by which time the ship's staff had established that Nos 2 and 4 Starboard Ballast tanks were breached as well as some cargo tanks. Further inspection established that the lower part of the pump room was flooding with an oily water mixture that was producing a gaseous atmosphere in this compartment.

D.1.5   The message summoning tug assistance was heard by the Port Signal Station. It was also heard by Milford Haven Coastguard, which was fortunate because HM Coastguard do not normally monitor VHF Channel 12. The Harbour Master was notified and the port's Emergency Plan was activated. In response, the previously designated members of the port's Emergency Team gathered at the Signal Station. Simultaneously the ship's managers, Acomarit, and MPCU were notified and responded by immediately putting in hand their own contingency plans to mobilise and travel to Milford Haven. The MEOR, located at Southampton, was activated under the direction of the Chief Executive of The Coastguard Agency who assumed the role of Overall Commander for the incident under the National Contingency Plan.

Narrative and Discussion - Master's Response

D.1.6   The Master's decision to counter the list was to fill the port side ballast tanks. The sea inlet valves in the pump room to the ballast system were now inaccessible, however, the branch lines between each ballast tank and the ballast main had isolating valves which, being controlled from the cargo control room, were accessible. It was possible therefore to cross flood these tanks. Whilst this gravitational method of partially filling the port ballast tanks was relatively slow it was effective in reducing the list. When the list was reduced to about 10° the ballast isolating valves were closed in order to prevent the draught of the casualty increasing further.

D.1.7   The Master kept Acomarit fully advised of the situation at regular intervals. By 2315 hrs he was able to fax them an initial condition report indicating that Nos 1, 2, 3, and 4 Starboard tanks, together with No 6 Centre tank, were damaged. Also that the status of Nos 1, 2, 3, 4, and 5 Centre tanks could not be determined. They were also advised that the list was 10° to starboard and the bottom of the pump room was damaged on the starboard side and flooding. Although the crew took no further direct action, throughout the salvage operation they continued to provide, whenever possible, all the services, machinery etc required to keep the casualty functioning. This was often carried out under difficult conditions.

Narrative and Discussion - Acomarit's Response

D.1.8   Upon being advised of the incident Acomarit, in addition to despatching three company superintendents to the casualty, contacted salvage brokers to arrange for salvage services. By 2305 hrs they were able to confirm that a LOF95 had been awarded to the salvage consortium.

D.1.9   Acomarit subscribes to Lloyd's Register of Shipping, Ship Emergency Response Service (SERS). With the computer model of SEA EMPRESS in their programme SERS are able to provide stability and residual strength calculations on a 24 hour basis. The first information concerning the casualty's condition was sent by Acomarit to SERS at 2330 hrs. At the same time Acomarit also copied information to MPCU. By midnight on Thursday SERS had completed the first computer runs for the vessel in the intact condition. Then several damage stability runs were made to try to reproduce on computer the draughts and angle of list which had been reported. The results were discussed with Acomarit and SERS were requested to await further instructions. At about 0700 hrs on Friday morning SERS were provided with the latest reported draughts of the vessel. However, these differed significantly from those computed, indicating that more accurate information and further calculations would be required. Also at this time Acomarit advised SERS that they were considering lightening the intact tanks first. At 0855 hrs SERS were stood down but later advised that they would be required to run a check on the salvors' proposals.

Narrative and Discussion - Salvor's Response

D.1.10   Cory Towage had their harbour tugs and their local Fleet Manager already in attendance while Klyne Tugs mobilised their ANGLIAN DUKE (100 tbp) and ANGLIAN EARL (84 tbp) to Milford Haven, the ETAs being 0800 hrs Friday and 0800 hrs Saturday respectively. Smit Tak, in anticipation of being awarded an LOF had already diverted their salvage vessel SMIT ORCA to Newhaven to land a salvage team of six people that would travel directly to Milford Haven. SMIT ORCA arrived at Newhaven at 0400 hrs on Friday and after disembarking the salvage party proceeded to Milford Haven. Meanwhile a further team of six, including a Salvage Master and a naval architect, were being mobilised by charter flight from Rotterdam.

D.1.11   The potential need for lightening tonnage was recognised at an early stage by those ashore. Although there was no specific plan at this stage, Cory Towage sought the assistance of shipbrokers in the tanker market to determine the availability of suitable lightening tonnage. The initial response to enquiries was mixed for a number of reasons, however a number of suitable vessels were offered.

Narrative and Discussion - Response by the Authorities

D.1.12   Port Authorities, Local Authorities and Government Agencies have emergency plans to cope with major incidents which threaten the safety of life or are likely to cause environmental damage. These plans, in general terms, lay down the framework upon which the control of the incident will be exercised. The plans should be complementary for multi-jurisdictional incidents, clearly laying down the responsibilities and liabilities of the various organisations in any foreseeable major incident. In Section 12 of this Report the relevant sections of Milford Haven's Emergency Plan and MPCU's National Contingency Plan are discussed with particular emphasis on how appropriate these were in the SEA EMPRESS salvage incident.

D.1.13   An MPCU team led by the Head of Operations arrived in Milford Haven at about 0030 hrs on Friday. Under the terms of the National Contingency Plan he assumed the role of MPCU Local Commander and immediately entered into discussions with MHPA to progress matters. As MHPA recognised that they alone would be unable to cope with the at-sea pollution MPCU agreed to assume responsibility for this aspect.

D.1.14   The Master and the pilot of SEA EMPRESS recommended to the Emergency Team ashore that advantage should be taken of the rising tide to attempt to refloat the vessel and, if successful, re-anchor her in the deep water 'pool'. The Master and pilot were advised by a message from the Signal Station timed at 0055 hrs that the Emergency Team were in agreement with their proposal.

D.1.15   By floating free on the rising tide the casualty would not have to be pulled off the ground by tugs and the chances of further pollution would be minimised. The prime advantage of moving the casualty into the 'pool' was that she would be floating at all states of the tide in a stable condition, although with a large list, and would not be subjected to grounding stresses.

Narrative and Discussion - General  

D.1.16   SEA EMPRESS was free of the ground at 0204 hrs. With tugs STACKGARTH (43 tbp), TITO NERI (50 tbp), DALEGARTH (45 tbp) and THORNGARTH (45 tbp) holding her, combined with use of the casualty's main engine, she was manoeuvred into the 'pool' where the port anchor was let go at 0211 hrs. Later the starboard anchor was dropped and the cables ranged to improve the holding power (see Figure 3 Image 100k).

D.1.17   In order to gain a reliable understanding of the condition of the casualty the MPCU Local Commander boarded SEA EMPRESS at about 0300 hrs. He was accompanied by an MPCU adviser and the local Fleet Manager from Cory Towage, who was the senior representative for the salvors until the Smit Tak Salvage Master arrived on scene. In company with the casualty's Chief Officer, the MPCU adviser and Cory's local Fleet Manager undertook a general inspection of the deck and the information concerning the vessel's condition was relayed to the Harbour Master ashore. This information did not substantially differ from that which was previously known but which was to be proven inaccurate as a result of the inspection by the salvors about twelve hours later. It was reported that the only option was to maintain the vessel in her present position and undertake a lightening operation. This advice was a factor in establishing the criteria for the salvage operation.

D.1.18   At this time the main priority was to pump out the pump room in order to gain access to the valves to the cargo system. Provisions were then made through MPCU for the Marine Pollution Salvage Centre (MPSC), based in Milford Haven, which had already been alerted and had moved equipment out of its warehouse, for pumps, fans, etc and other equipment to be made available to pump out the pump room. This equipment was delivered to the casualty by the barge WICKNER at about 0600 hrs.

D.1.19   The MPCU Local Commander left the casualty at about 0600 hrs to return ashore. Once ashore he updated MHPA on the situation on board and gave advice on the planning of the response organisation. The response to the shore pollution was to be co-ordinated and directed by the Joint Response Centre. He agreed the organisation ashore for the salvage and marine counterpollution response. The response to the marine aspects of the incident, including the salvage operation, were led by MPCU with the assistance and involvement of MHPA. The management of these two aspects of the incident were later separated and a Marine Team, led by the Harbour Master, was formed to deal with the casualty and its salvage. (See Section 13 for full details of the onshore management.)

D.1.20   The Secretary of State for Transport through the MPCU, and the Harbour Authority, has considerable powers of direction and intervention if the actions of the Owners of the casualty or the salvors give rise for concern. Prior to the agreeing and signing of the LOF the Master was in sole charge of his vessel and it was only after the LOF had been agreed that the salvors became temporary custodians of the vessel. In the case of SEA EMPRESS the salvors were a consortium which included a team from Smit Tak, who were going to provide the Salvage Master. However, the team from Smit Tak would not be arriving in Milford Haven until about midday on Friday 16 February and, in the interim, decisions on what to do with the casualty and what could be reasonably undertaken as first aid measures prior to the salvors being fully in control of the situation had to be considered.

D.1.21   There were disadvantages in holding the casualty in the 'pool' due to the relatively exposed location and the strength of the tides. Pending the arrival of the Smit Tak team the principals involved on site discussed other alternatives. These were to take the casualty to sea, beach her or take her directly to the berth at Herbrandston Jetty but all of these alternatives had their attendant risks.

D.1.22   Taking the casualty to sea into predicted adverse weather may have resulted in her foundering, with a risk to life, before reaching deep water. This would have resulted in not only the vessel being lost, but the entire cargo escaping and polluting the coastal region and local fishing grounds.

D.1.23   Beaching a distressed vessel is, in certain circumstances, a viable option used by salvors. Not only does this obviously prevent foundering but it allows the vessel to be held in relative safety until the salvors are able to mobilise their manpower and equipment. However it has to be carried out in controlled conditions and the site of the beaching and all the relevant circumstances need to be carefully considered. The beaching site is selected not only for the nature of the bottom material but also with respect to its ability to properly support the vessel for the whole of it length. Ideally the final selection of the site would follow a survey of the location by divers. Matters such as tidal range and ballasting have to be examined, taking account of the particular circumstances of the matter. In the case of a damaged laden tanker the tidal drop must not permit oil to escape. Ballast must be adequate to hold the vessel from moving but not so restrictive to prevent the vessel being refloated. Further, the location should provide adequate shelter from the weather and the sea to permit access and work to be undertaken on the vessel. There are a number of bays in the Milford Haven area which fulfil these requirements.

D.1.24   To take the vessel directly to the berth at Herbrandston Jetty (a designated safe berth for casualties) the controlling factor was the draught of the casualty. SEA EMPRESS was listing to starboard with a maximum observable draught of 23.5 metres, therefore even with the six metres of tide predicted for 0342 hrs on Friday the vessel's draught was too great to move very far from the 'pool'.

D.1.25   All three alternatives were ruled out, at least for the time being, because the lowest risk lay in leaving the casualty where she was, in the 'pool'.

D.1.26   Despite TITO NERI (50 tbp) parting the tow line at 0615 hrs and having to reconnect, the period after the vessel was relocated was without major incident. At about this time the pilot, who had been on board since boarding the vessel on her arrival off Milford Haven, was joined by another pilot and there were further reliefs later with sometimes two pilots being on board. During this time the pilots continued to hold the casualty in the anchored position with the aid of the four harbour tugs and the casualty's engine.

D.1.27 During the morning the situation was discussed by the three pilots on board the casualty. They were concerned that with the worsening weather forecast and increasing strengths of tides, as the tidal cycle moved towards springs, they would need more tugs and/or ground tackle to hold the casualty in her present position. Their preferred option was for her to be taken out to sea or, if the list and trim could be reduced, to Herbrandston Jetty. These concerns and the pilots' consideration of the options were communicated to the Deputy Harbour Master at about 1130 hrs.

D.1.28   There was some mooring equipment available at Pembroke Dock and the MPCU adviser informed the Cory local Fleet Manager in the early hours of Friday morning of these resources. Whether this equipment was suitable for the purpose of holding a vessel of the size of the SEA EMPRESS was not established at that time. The Cory local Fleet Manager was reluctant to initiate further salvage activities other than ordering pumps etc pending the arrival of the Smit Tak Salvage Master.

D.1.29   At about 0800 hrs ANGLIAN DUKE (100 tbp) arrived on scene and was made fast to the casualty but almost immediately parted her 42mm wire pennant and had to resecure using a 62mm wire pennant. With the arrival of ANGLIAN DUKE (100 tbp) the collective available nominal bollard pull was 283 tonnes.

D.1.30   By 1100 hrs, to the credit of all those involved, all the equipment necessary to pump out the pump room had been off loaded from the barge WICKNER and the pumps rigged ready to lower within the pump room by MPSC staff. However the MPCU adviser ordered the operation to be stopped because he considered that it was unsafe.

D.1.31   At 1130 hrs the Salvage Master from Smit Tak arrived at Milford Haven and met with the Harbour Master, MPCU, and Acomarit's representatives, when he was informed about the reported condition of the casualty. By 1215 hrs the salvage team from Smit Tak was on board SEA EMPRESS assessing the situation and at about 1220 hrs the Director of MPCU, arrived at Milford Haven and took over as MPCU Local Commander.

Conclusions

D.1.32   Without exception all the organisations, companies and individuals concerned in responding to the casualty did so promptly.

D.1.33   The prompt action of the Master of SEA EMPRESS in ballasting the port side tanks is to be commended. Calculations undertaken since the incident show that without the prompt instigation of remedial measures the vessel would have developed a 30° list, thus making the initial situation far worse.

D.1.34   The decision to move SEA EMPRESS from the initial grounding position to the 'pool' on the morning of the 16 February was prudent and reasonable, given the information available at the time.

D.1.35   The extreme draught of the casualty severely limited the options which were available for dealing with the emergency. The decision to leave the casualty in the 'pool' at this stage of the incident and not take her to sea, nor beach her, was correct. However at this stage no attempt was made to determine to what minimum value the draught could be reduced. Given the ready access to SERS by the Marine Team this is surprising. As a result only two practical salvage options were known to MPCU and MHPA, namely to hold the casualty in the 'pool' and lighten her, or to take her to sea. The possibility of taking the casualty directly to Herbrandston Jetty without prior lightening was not fully explored. This possibility is discussed in Section 15.

SALVAGE STRATEGY AND EXECUTION - PERIOD 2

General

D.2.1   Period 2 covers the time from 1300 hrs on Friday 16 February to 1830 hrs on Saturday 17 February.

During this time the weather conditions at the casualty slightly deteriorated. The wind remained westerly but increased to force 6 towards the end of the period with gusts of force 8.

The weather forecasts issued at 1531 hrs and 2041 hrs on Friday 16 February predicted that the northwest-by- west wind of force 4/5 occasionally force 6 would decrease to force 4/5 for late Friday and early Saturday morning. The 0518 hrs forecast on Saturday 17 February predicted an increase to force 5 with gusts to force 7 for the remainder of this period.

The 0518 hrs extended forecast predicted that during Saturday evening the southwest-by-west wind force 4 would increase to force 7, gusting 9 by midnight and would veer to west-northwest by 0600 hrs Sunday.

Predicted high water at Milford Haven on Friday was at 1614 hrs with low water at 2243 hrs. On Saturday predicted high water was at 0442 hrs, low water at 1109 hrs and high water at 1708 hrs.

Sunset on Friday was at 1737 hrs, with sunrise and sunset on Saturday at 0730 hrs and 1739 hrs respectively.

D.2.2   During Friday and Saturday the MPCU team was reinforced with more personnel and a senior MPCU adviser arrived at Milford Haven to strengthen the team of salvage advisers. Senior personnel from Acomarit arrived, as did numerous solicitors, consultants and surveyors representing the various interested parties. A Marine Response Centre (MRC) based within the Coastguard Station became the hub of all shore based activities concerning the casualty and its salvage and was where most interested parties assembled.

Narrative and Discussion

D.2.3   On boarding the casualty at about 1215 hrs the Smit Tak Salvage Master expressed reservations about the current assessment of the damage and, following a brief meeting with the Master and others, commenced an examination of the casualty. By 1530 hrs the salvors had gained sufficient information to be able to state that the casualty's condition was not as previously determined. In essence the damage was confined to NoÊ1 Centre Cargo tank, Nos 1, 3 and 5 Starboard Cargo tanks, plus No 6 Starboard Slop tank, Nos 2 and 4 Starboard Ballast tanks and the pump room, all being open to the sea.

D.2.4   Based upon this information the salvors' basic plan, as explained to the Acomarit representative and representatives of the various authorities on board, was to:

- regain control of the flooded pump room;

- test the casualty's inert gas and cargo pumping systems;

- lighten cargo from the centre tanks into a suitable vessel;

- transfer cargo out of the damaged tanks over the top (into the centre tanks) to improve the water plug;

- pressurise the damaged tanks with inert gas;

- undertake a diving survey to check on bottom damage;

- move the vessel to an appropriate berth once the draught had been suitably reduced in order to discharge the balance of the cargo.

D.2.5   In the subsequent discussions on board the Salvage Master considered the idea of taking the casualty to sea but explained that he was opposed to it because he considered it to be an unacceptable risk.

D.2.6   The Salvage Master was advised of the local resources which were available from MPCU and the Admiralty Salvage and Mooring Depot at Pembroke Docks.

D.2.7   In order to regain some of the buoyancy on the starboard side it was the salvors' intention to transfer some of the cargo over the top from the damaged tanks and then to slightly over-pressurise them with inert gas. To undertake this process it was necessary to mobilise the necessary plant and equipment and to have blank flanges with gas connections manufactured to seal the pressure/vacuum valves and other openings on deck. Whilst these preparations were being made the salvors lashed the pressure/vacuum valves closed in order not to lose the remaining inert gas in those tanks.

D.2.8    STAR BERGEN had been chartered as a lightening tanker, and would be available for use from 0600 hrs on Saturday. It was anticipated that the transfer operation would commence at 1100 hrs when the lightening vessel was alongside SEA EMPRESS and, subject to weather conditions, the operation was expected to last for 24 to 30 hours.

D.2.9   To facilitate a speedy and safe transfer of the cargo from the casualty's centre tanks to the lightening tanker it was intended to use the main pumps of the SEA EMPRESS. However, this required the water in the pump room to be pumped out and the space to be ventilated because the atmosphere was well within the explosive range. This operation, which had previously been halted on the orders of the MPCU adviser, was recommenced at about 1400 hrs by the salvors using the pumps and equipment previously provided by MPCU. Two submersible pumps were used and ventilation had to be provided by portable units. This was necessary because the lower end of the compartment's ventilation trunking was below the water level. Until the water level was lowered sufficiently to uncover the trunking the casualty's own ventilation system could not be used.

D.2.10   A list of further equipment needed for the operation was telephoned to the Smit Tak office in Rotterdam for prompt transportation by lorry. Further salvage equipment, including pumps, diving gear and an inert gas generator was on board SMIT ORCA which was expected to arrive at Milford Haven at about noon on Saturday.

D.2.11   Despite the Marine Team having representatives on board the casualty who had been advised of the salvors' plans and intentions, the Marine Team ashore exhibited a degree of frustration at the operation's apparent slow start. At about 1800 hrs the Assistant Salvage Master went ashore at the request of MHPA to explain the salvage plan. In addition to presenting the broad outline, he gave the Salvage Master's reasons why it had been decided not to take the casualty to sea.

D.2.12   Despite the inspection of the casualty by the salvors, which showed that the damage was not as previously reported, the general consensus throughout was that the casualty must be lightened before it would be allowed to proceed to Herbrandston Jetty. The maximum draught for a passage to this jetty, allowing for a 10% safety margin which is required by MHPA, was being taken as 18.3 metres. It is apparent that this figure was based simply on the minimum charted depth alongside the jetty and did not take into account other factors such as height of low water that would have been expected alongside the jetty. To achieve this draught it was accepted that some cargo at least must be lightened before passage to the jetty could be undertaken.

D.2.13   Between 0300 hrs and 0500 hrs on Saturday locally obtained equipment and that supplied by MPCU, including an inert gas generator, a power pack and two compressors, were delivered on board SEA EMPRESS. At about 0600 hrs the Assistant Salvage Master went to the Milford Haven Dry Dock, where work had been undertaken throughout the night manufacturing the blanks and gas connections, to check on progress and present a further list of requirements. Shortly afterwards the Salvage Master updated the Assistant Salvage Master by telephone of the progress on board during the previous night. This information was conveyed to the Harbour Master and MPCU at the morning meeting held in the Coastguard Station. At a subsequent meeting that morning the Harbour Master agreed to the casualty being brought into the Haven after the draught was reduced. This would involve transferring between 25,000 and 30,000 tonnes of cargo into STAR BERGEN whilst the casualty remained in the 'pool'.

D.2.14   Concern was expressed about controlling the casualty in the predicted wind and sea and the strong northeast/southwest tidal stream with the available tugs. However, the salvors gave the assurance that with two further tugs due to arrive on scene on Saturday morning (ANGLIAN EARL (84 tbp) and ESKGARTH (50 tbp)) they would have a total nominal bollard pull of 417 tonnes available and they considered this was enough for their purpose.

D.2.15   Some difficulty had been experienced in controlling the casualty in the wind, sea and tidal conditions that existed during the night. In the early hours of Saturday a suggestion evolved between an MPCU adviser, a representative of Cory's and a pilot on board SEA EMPRESS that the casualty should be turned around to face the gale that was predicted for later that day. It was generally considered to be good seamanship to turn the bows of the casualty into the weather and at about 0800 hrs this suggestion was put to the Salvage Master. The matter was also discussed with the relief pilots and Cory's Fleet Manager. Nobody was opposed to the idea and it was collectively agreed that the turn should take place during slack water on the high tide that afternoon.

D.2.16   By 0900 hrs the water level in the pump room had been lowered sufficiently to permit the use of the compartment's own ventilation system. Pumping to lower the water level continued, the pumps being regularly adjusted to avoid discharging any oil that was on the surface of the water, until about 1345 hrs when the water was level with the floor plates on the starboard side.

D.2.17   At about 1100 hrs a meeting was convened on board by Cory's Fleet Manager and attended by Smit Tak's Salvage Master and Naval Architect, the Masters of THORNGARTH (45 tbp) and TITO NERI (50 tbp), two Acomarit representatives, the Master and Chief Officer of SEA EMPRESS, an MPCU adviser and two pilots. The discussion was based on how and when the proposed turn would be executed, not whether it should be undertaken. There was no disagreement regarding the requirement to turn the vessel, either from those concerned on board or from the authorities ashore. One of the pilots had taken it upon himself to compile a sequence of events for the turn and this was presented to the meeting. The subsequent discussion was on an ad hoc basis, however all those present agreed on how the operation was to be undertaken.

D.2.18   At 1300 hrs SMIT ORCA arrived and within an hour had off-loaded an inert gas plant. She was then designated to provide an operational base close to the casualty for the salvors.

D.2.19   At 1402 hrs, three hours and six minutes before predicted high water, with seven tugs connected (ANGLIAN DUKE (100 tbp), ANGLIAN EARL (84 tbp), TITO NERI (50 tbp), ESKGARTH (50 tbp), STACKGARTH (43 tbp), DALEGARTH (45 tbp) and THORNGARTH (45 tbp)), the turning operation commenced by starting to weigh the starboard anchor. At about 1406 hrs with one shackle remaining on the starboard cable, the heaving of the port anchor commenced. At 1429 hrs it was realised that the anchor cables were fouling each other and efforts to free them were unsuccessful. Mindful of the limited time before slack water it was decided to continue the operation despite the anchors possibly still touching the bottom.

D.2.20   The turning manoeuvre continued until the casualty was heading towards the entrance to the Haven and moving towards the southwest corner of the 'pool'. It is reported that at this time the more experienced pilot, without prior consultation with the Salvage Master, telephoned the Harbour Master advising that the casualty was in a position to be taken to sea, presumably inferring that he wanted instructions to this effect. The Harbour Master agreed with the pilot that he too would like to see the casualty taken to sea. However, the Harbour Master's view was that it would be unsafe to do so and taking into consideration the advice of members of the Marine Team he stated that the casualty should not be taken out to sea. It should be noted that the salvors had already expressed their reluctance to take such action.

D.2.21   Having turned the casualty the pilot positioned her, as he had planned, in the extreme southwest corner of the 'pool'. Once in position the anchors, which were still crossed, were paid out to 11 shackles each. This operation was aided by the seven attending tugs, although THORNGARTH (45 tbp) was now pushing on the starboard quarter, having parted her line earlier.

D.2.22   The intention had been for the casualty to lie in the centre of the 'pool' with the forecasted gale force wind just on the starboard bow. As the anchor cables were walked back the tugs, assisted by the casualty's main engine, moved the casualty astern and into position. When the anchor cables had been paid out to 11 shackles which was completed by 1636 hrs, the process of redeploying the tugs against the forecast bad weather commenced (see Figure 3 Image 100k). Thereafter followed a sequence of events which dramatically changed the course of the salvage operation.

D.2.23   At about 1705 hrs DALEGARTH (45 tbp) was ordered to reposition on the port quarter in accordance with the predetermined plan for holding the casualty in the forthcoming gale. However DALEGARTH (45 tbp) had a problem in making fast and was set down onto ANGLIAN DUKE (100 tbp) resulting in minor structural damage to DALEGARTH (45 tbp) and the loss of her tow line. At the same time THORNGARTH (45 tbp) was dispatched to pick up a replacement towing rope thus for a short time leaving five tugs to attend the casualty. At 1735 hrs after receiving a new rope THORNGARTH (45 tbp) made fast on the starboard quarter.

D.2.24   At 1745 hrs the pilot who was plotting the casualty's position detected that she was drifting out of position by which time the ebb tide had begun to take effect. The main engine and steering gear were employed in an attempt to arrest the casualty's drift. The change in the tide put it in opposition to the wind, creating a short sea which made it difficult for the tugs to maintain station and caused the tow lines to snatch. As the ebb tide strengthened the casualty began to drift towards the west. At 1755 hrs, following the shortening of the tow line prior to its repositioning, ANGLIAN DUKE (100 tbp) was instructed to apply full power. Compliance with this order resulted in the tow line parting, to be followed by that of TITO NERI (50 tbp). At 1800 hrs DALEGARTH (45 tbp) made fast on the port quarter but the tugs were unable to arrest the bodily drift of the casualty as she moved to the west, on a southerly heading, into shallower water. The movement of the casualty seemed to surprise everybody; it had been thought that the direction of the tidal stream was in line with the channel, not across it, and the strength of the tidal stream at that time was far greater than anticipated. The casualty had been positioned, inadvertently, with the force of the ebb tidal stream acting on her port side.

D.2.25   In a preceding section of this Report (Section 4) reference is made to a numerical model which describes the tidal streams in the 'pool'. It is apparent, from this model, that the ebb tidal stream runs in a westerly direction across the major part of the 'pool'.

D.2.26   The computer generated model of the tidal streams at the entrance to Milford Haven suggest that, following the turn, the velocity of the ebb tidal stream in the vicinity of the casualty was nearly 50% greater than before. This difference was due mainly to the increasing strength of the tides as they approached springs and partly to the casualty having been repositioned slightly further south and west. The effect of this increase in tidal velocity would have been to approximately double the tidal forces exerted on the casualty. It has been calculated that the maximum force on the casualty's underwater hull form, due to the tidal stream on the beam, had increased to a figure in the order of 570 tonnes. This force would have increased still further as the casualty was carried into shallower waters and probably exceeded 700 tonnes before the casualty grounded. It is clear that even if the assembled tugs had been deployed against this unexpected tidal stream, their combined nominal bollard pull of 417 tonnes was inadequate for the circumstances which actually prevailed.

D.2.27   As SEA EMPRESS drifted out of control she had become beam on to the tidal stream. She grounded on Saint Ann's Head Shoal at 1805 hrs. It was concluded that the anchors, which were leading out on the port bow, were affecting the ability of the after tugs to turn the stern of the casualty into the tidal stream, so lessening the forces on the hull. A decision was made, principally by the more experienced pilot, to slip the anchors so that the stern could be towed to the east and allow the bows to fall off to the west. This was agreed by the Master and the Salvage Master.

D.2.28   The Smit Tak salvage crew under the Salvage Master's instructions released the bitter ends of the anchor cables at 1812 hrs. However, with the anchor cables slipped, the casualty did not behave as had been predicted and the tugs were unable to refloat her. The casualty was fast aground with the stern about 2.5 cables southwest of Saint Ann's Head Lighthouse on a falling tide (see Figure 3 Image 100k).

Conclusions

D.2.29   With the arrival of the Smit Tak team and their re-assessment of the damage to the casualty consideration was given by them to the various options for the salvage of the casualty. However, discussions with the Marine Team resulted in the decision being taken to leave the casualty in the 'pool' and lighten her as agreed earlier.

D.2.30   The decision by all parties to turn the casualty was understandable and based on good seamanship practice and the available information. However, the principal reason for the loss of control of the casualty after the turn on Saturday was that not enough consideration was given to the effect of the tidal stream and she was positioned further south and across the direction of the ebb tide.

D.2.31   The most important factor in the loss of control of the casualty was that the exact nature of the tidal pattern in the vicinity of the southern area of the 'pool' was not fully understood by all concerned.

D.2.32   The decision to slip the anchor cables, which with hindsight may be shown to have been unfortunate, was an operational decision that had to be made rapidly and was taken in good faith with the expectation that it would resolve the immediate problem.

D.2.33   The decision not to take the casualty to sea, because it was considered too dangerous, was correct.