MT Sea Empress incident timeline
Ivan LinnikThe text below might contain errors due to inserted from scanned pages. Content was slightly edited and some articles highlighted for smooth reading.
You can find original incident investigation report here.
Narrative
SEA EMPRESS loaded her cargo of Forties Light Crude Oil at Hound Point, in the Firth of Forth and sailed from there for Milford Haven on 13 February 1996. All the cargo tanks were filled to normal capacity, with recorded ullages on completion of between 1.08 and 1.40 metres. The vessel’s figure for cargo on board was 130,018 tonnes. The dedicated ballast tanks had been emptied except for about 890 tonnes in the Aft Peak tank, for trim purposes. A route via the English Channel to Milford Haven was decided upon and a sea passage plan was prepared to a position 4.5 miles south-southwest of the entrance to the West Channel to Milford Haven. This position was designated ‘Way Point 20’.
Thursday 15 February
The three deck officers and the helmsman/lookouts were keeping the conventional four-on eight-off watch rota. The Master was not standing a watch. During the sea passage, on 15 February, a pilotage passage plan into Milford Haven was prepared. This plan started from ‘Way Point 20’ with a course almost coincident with the line of the Outer Leading Lights to the West Channel entrance and continued with further courses up the West Channel and thence into the port. The Tanker Check List and Pilot Card were also prepared for arrival at Milford Haven.
‘End of Sea Passage’ was at 1905 hrs on Thursday 15 February when SEA EMPRESS was 7.5 miles south-southwest of the West Channel entrance and steering a course of Both steering gears were running and the main engine was on bridge control. At 1910 hrs course was altered to 01 towards the boarding area requested by the pilot, which was four miles southwest of Saint Ann’s Head. The wind was west-northwesterly force 4/5 and it was fine and clear. Engine speed was gradually reduced and the vessel was then manoeuvred to maintain a boarding speed of about 5 knots and a starboard lee for the pilot, who boarded at 1940 hrs. At this time SEA EMPRESS was 3.8 miles southwest of Saint Ann’s Head on a heading of and the main engine was on ‘dead slow ahead’. The Bosun had cleared the anchors for letting go and the bow mooring party went forward, followed by the Third Officer who had escorted the pilot to the Bridge and would take charge forward.
On arrival on the bridge, which was manned by the Master, Chief Officer and helmsman, the pilot inspected the information on the Tanker Check List and Pilot Card, which he found in order. The arrival draught had been reported by the Master as 15.9 metres, with the vessel on an even keel. The pilot expected the tidal stream to seaward of the West Channel to be slack at this time, but there was still an outgoing tide running in the Channel, the predicted time of low water in the port being 2130 hrs. At 1944 hrs the pilot ordered 'full ahead' and a turn to starboard to a course of approximately. At 1948 hrs the vessel was 2.75 miles southwest of the Channel entrance and working up to full manoeuvring speed.
At 1951 hrs the vessel was 2.3 miles southwest of the Channel entrance and the pilot could see both Outer Leading Lights and both Inner Leading Lights for the West Channel (see Section 4 for detailed description of the entrance to Milford Haven). At about 1955 hrs he ordered progressive changes of course to port, by about at a time, until the vessel was on a heading of a position plotted by the Chief Officer at 2000 hrs showed the vessel to be one mile from the entrance to the Channel and about midway between the lines of the Outer and Inner Leading Lights. The pilot was steering the course of in order to make a judgement as to which way the tide was likely to affect the vessel. He was satisfied with the performance of the helmsman and had the impression that the course of was being made good. The speed made good had increased progressively to about 10 knots.
According to published tidal information, the east-southeast running tidal stream to seaward of the Channel entrance was predicted to begin at about 2000 hrs. When SEA EMPRESS was two or three cables from the Channel entrance, the pilot saw from the changing aspect of the Outer Leading Lights that there was a set to the east. He ordered a course change of to port. The vessel, which was now closing with the Mid Channel Rocks Light Buoy, started to turn to port. The pilot saw the Outer Leading Lights close and then open to the east (that is, the rear Leading Light appeared to move to the right of the front Leading Light) as the bows entered the channel. The Buoy was very close to starboard and the pilot now saw that the fixed red and fixed white lights of the Outer Leading Lights, the ones indicating the east side of the deepest water in the Channel entrance, were also open to the east.
After the bows had passed the Middle Channel Rocks Light to starboard there was a shuddering vibration, then a sound from the deck below of liquid being forced under pressure, accompanied by a strong smell of oil.
The time was 2007 hrs. The helmsman reported that the vessel was not steering and the pilot ordered 'full astern', both anchors to be let go and called out the four harbour tugs which were waiting to assist SEA EMPRESS to her berth. At 2008 hrs the Chief Officer recorded this order and the vessel's position, which was 1.4 cables northwest of Middle Channel Rocks Light. SEA EMPRESS, which was trimming by the head and taking a starboard list, continued to run ahead as the anchors were let go. There were further main engine movements and the vessel finally lost all way at approximately 2015 hrs after she grounded again in a position about 3.3 cables southby-west of the Mill Bay Buoy (see Figure 2). The main engine was put to ‘stop’. SEA EMPRESS was by this time significantly trimmed by the head and had taken an list to starboard with the starboard fore part of the deck awash and was heading in a northwesterly direction.
The engineers in the engine control room felt the vessel vibrate very heavily. The starboard list then caused a number of alarms to sound in the engine control room and both the port and starboard boilers shut down automatically due to the extent of the list. The main engine and alternators, however, remained fully operational with no alarm condition being recorded. The starboard boiler was re-started and the engine room and steering gear compartment were checked for damage and leaks. None were found.
In response to the pilot’s request the four waiting tugs proceeded to SEA EMPRESS with all speed. By about 2023 hrs the tugs DALEGARTH and THORNGARTH had made fast their lines to the bow of the casualty and TITO NERI and STACKGARTH were instructed to standby off each quarter in case the crew had to be evacuated. However the Master decided that, because SEA EMPRESS appeared to be in no immediate danger, the crew would remain on board.
Initial reports of a damage assessment, undertaken by the casualty’s crew, indicated that Nos 1 & 3 Starboard and No 6 Centre Cargo tanks together with Nos 2 & 4 Starboard Ballast tanks had been damaged. Some flooding of the pump room was also indicated. The casualty’s initial angle of list, recorded as to starboard at 2024 hrs was reduced to about by running sea water into the two port side ballast tanks, Nos 2 and 4, under gravity from the damaged starboard side ballast tanks via the ballast main. An offer of salvage assistance by a consortium comprising Smit Tak BV, Cory Towage Limited and Klyne Tugs (Lowestoft) Limited on the terms of Lloyd’s Standard Form of Salvage Agreement “No Cure-No Pay” 1995 Edition (LOF95) was accepted by Acomarit, the managers of SEA EMPRESS, by 2305 hrs. (See Annex A for general details of marine salvage and LOF, and Annex B for general details of the Government’s role in a major incident.)
Friday 16 February
By 0040 hrs on Friday 16 February STACKGARTH and TITO NERl were made fast to the stern of the casualty. The Master and the pilot agreed that SEA EMPRESS should be manoeuvred into the deeper waters of the ‘pool’ where she could be held by the tugs. It was also decided to reposition the anchors. These proposals were passed to the Signal Station at 0055 hrs. High water at Milford Haven was predicted to occur at 0342 hrs.
Commencing at 0127 hrs, the anchors were weighed and with the assistance of the four tugs and the casualty’s engine and steering she was moved to the southwest into the ‘pool’ and onto a northeasterly heading. The port anchor was let go at 0211 hrs but as sea conditions were deteriorating slightly it was decided to let go the starboard anchor also. By 0427 hrs the two anchor cables had been laid out and the engine stopped (see Figure 3). The tugs were experiencing difficulties with their lines parting but they were reconnected and the casualty’s position was maintained.
At this stage SEA EMPRESS was considered to be in a stable condition and under control.
However, there was some debate within the Harbour Authority on the advisability of ordering the casualty out to sea as soon as possible but this idea was dismissed.
Representatives of the Marine Pollution Control Unit (MPCU) of The Coastguard Agency had began to arrive in the Milford Haven area from about 0030 hrs. MPCU staff boarded SEA EMPRESS with a local representative of Cory Towage and made an assessment of the casualty’s condition. As a result of this assessment MPCU recommended to the Harbour Master that SEA EMPRESS should be held in position and lightened.
One of the first objectives of the salvors was to regain control of the pump room which was flooded to a level of about 5 metres and had a flammable atmosphere. Power packs, pumps and other equipment from the Marine Pollution Salvage Centre (MPSC) in Milford Haven were mobilised and at 0600 hrs began to arrive on board SEA EMPRESS. At 0800 hrs the tug ANGLIAN DUKE arrived and increased the number of tugs made fast to the casualty to five. The presence of a pilot was maintained on board. The tanker STAR BERGEN was on charter to the salvors for an anticipated ship-to-ship transfer of oil.
In the course of the morning various options for the movement of SEA EMPRESS were considered at meetings held on board and ashore. Shipboard discussions resulted in two options being proposed; either taking the casualty to sea or reducing the angle of list and the draught to bring her further into the Haven. A number of indicators pointed to the need for a lightening operation and preparations to lighten the casualty continued. The time chosen for the commencement of this operation was 1100 hrs on Saturday 17 February in order to take advantage of slack water and daylight. However, a forecast of a period of poor weather suggested the lightening operation might have to be delayed. The Salvage Master and a team from Smit Tak arrived at Milford Haven at 1130 hrs.
By 1530 hrs portable MPCU pumps and fans were in place pumping floodwater from the pump room and venting it in order to ensure the atmosphere was safe for entry. By this time the Smit Tak Salvage Master had made his assessmerit of the casualty’s condition. The essential elements of the salvage plan chosen by the Salvage Master consisted of pumping out the undamaged centre tanks to a lightening vessel, transferring cargo from the damaged starboard tanks into the centre tanks using portable pumps and pressurising the damaged starboard tanks with inert gas. The objectives of this plan were to right the casualty, reduce its draught and remove cargo from the damaged tanks to prevent pollution. SEA EMPRESS would then be in a suitable condition to be taken to a berth alongside to complete total discharge of cargo.
Efforts by the salvors continued on board SEA EMPRESS, throughout the remainder of Friday, to achieve this end. Weather conditions deteriorated during the afternoon and evening, however the casualty’s position continued to be maintained at anchor in the ‘pool’, with the use of tugs and the casualty’s own main engine.
Saturday 17 February
Concerns over the deteriorating weather, forecasts of a gale and the anticipated difficulty of holding the casualty’s stern to the weather were coupled with a desire to give a lee on the port side to assist the lightening operation. These resulted in a decision being made to turn the vessel during the slack water period of Saturday afternoon, 17 February, so that it headed seawards and with the anticipated gale on the starboard bow.
Two further tugs, ESKGARTH and ANGLIAN EARL, had arrived in Milford Haven by 0900 hrs and stood by. Pumping and ventilation operations in the pump room had continued and it was declared safe for entry at 1330 hrs.
Much of the efforts of Saturday morning were directed in the planning and preparation for the turning of the casualty. The operation to turn SEA EMPRESS commenced at 1400 hrs with the manoeuvre under the overall control of a pilot. A total of seven tugs, ANGLIAN DUKE, THORNGARTH, TITO NERI, DALEGARTH, STACKGARTH, ANGLIAN EARL and ESKGARTH, all had lines secured to the casualty. Difficulty was experienced in recovering the anchors of SEA EMPRESS and it was suspected that they were fouled. They could not be brought right ‘home’ and about one shackle (30 metres) of cable was left from the ends of the hawse pipes. As SEA EMPRESS swung she pointed seawards. The possibility of taking the casualty out to sea was raised by the pilot but the considered opinion of those ashore was that it would be too risky. The turn of SEA EMPRESS was completed at 1555 hrs with the casualty in the southwest corner of the ‘pool’. Both of the casualty’s anchor cables were then walked out until 11 shackles were streamed on each cable but they were still crossed.
At 1700 hrs, with the casualty heading approximately west-southwest, it was decided to reposition the tugs in preparation for the forecast poor weather. During these manoeuvres SEA EMPRESS started moving to the west under the influence of the ebb tide. Efforts to arrest this movement by the tugs resulted in at least two tow lines parting. SEA EMPRESS continued to move beam on to the tide, in a westerly direction.
In spite of the use of the casualty’s main engine and the efforts of the tugs she grounded off Saint Ann’s Head at about 1805 hrs.
Both anchor cables of the casualty were then slipped in an attempt to free the bows and allow the stern to be towed up into the tide. The wind was reported as being from the west-southwest, force 6/7.
Due to the casualty’s situation, including the loss of her anchors, a request for more tugs was made by the salvors. The tug DE YUE was reported as having departed Falmouth with an ETA at Milford Haven of 0800 hrs on Sunday 18 February. With 54 personnel on board the casualty it was also decided to evacuate non-essential personnel and this operation commenced at 1910 hrs by helicopter with a second lift at 1950 hrs. Further assessment of the situation led to a decision being made to secure the casualty by the bows in her present position by ballasting, so increasing her ground reaction. The casualty’s ballast system was prepared and filling of the Fore Peak and No 2 Port Ballast tanks commenced; inerting of the damaged cargo tanks also began at 2245 hrs.
Sunday 18 February
At midnight the wind was reported as being from the west-southwest, force 9 with a heavy westerly swell. Filling of the ballast tanks continued into the early hours of Sunday morning.
Weather conditions were deteriorating and were reported at 0200 hrs as 40 to 50 knot westerly winds; these increased later to 60 knots.
Two further tugs, YEWGARTH and ELDERGARTH, arrived in Milford Haven at 0230 hrs and at 0240 hrs a further group of people was evacuated from the casualty by helicopter.
On the rising tide the casualty started to work in the seaway and generate noises which were associated with structural failure. A decision was made to evacuate the casualty and the remaining 14 persons on board were airlifted from her by 0440 hrs. All tugs, except ANGLIAN DUKE and ANGLIAN EARL, were released due to concern for their safety and the possibility of a fire or explosion on SEA EMPRESS. ANGLIAN DUKE and ANGLIAN EARL remained secured to SEA EMPRESS by 750 metres and 650 metres of wire respectively. The main lighting of SEA EMPRESS was seen to fail, and emergency power take over, at 0607 hrs. At about 0800 hrs the casualty floated off and drifted to the east across the channel.
SEA EMPRESS was again reported aground at 0840 hrs, in a new position, further southeast by Middle Channel Rocks, after having been driven across the West Channel and the ‘pool’. DE YUE, which had arrived shortly after 0900 hrs and had a pilot and a Klyne tug master on board, spent a period on trial manoeuvres at the stern of SEA EMPRESS. She then anchored in Dale Roads at 1140 hrs and prepared her towing gear. A small group of salvors were airlifted to SEA EMPRESS in order to handle tug lines. They also attempted to restore the casualty’s main power but these attempts proved unsuccessful, even with radioed advice from the casualty’s Chief Engineer. The conditions at the casualty were very poor with a westerly wind gusting gale force. DE YUE again approached the stern of SEA EMPRESS at 1520 hrs and a line was secured with the assistance of a helicopter. SEA EMPRESS was observed drifting in a northeasterly direction between 1500 hrs and 1600 hrs. ANGLIAN DUKE, TITO NERl and ESKGARTH were instructed to assist DE YUE who in turn requested guidance from the shore authorities on action to be taken but no positive instructions were received. The salvors left SEA EMPRESS by 1715 hrs aground in a position approximately 6 cables northeast of Middle Channel Rocks Light, but clear of the West Channel, at the northeast end of the ‘pool’.
Additional Smit Tak salvage crew, including a Senior Salvage Master, arrived in the Milford Haven area during the Sunday afternoon. It was accepted that there was little possibility of lightening SEA EMPRESS during the following day.
Monday 19 February
At 0044 hrs, after having experienced great difficulties in maintaining position and threatened with grounding herself, DE YUE slipped her tow line and proceeded to an anchorage.
SEA EMPRESS was reported as moving towards Middle Channel Rocks at 0810 hrs where she later grounded. MPCU staff, salvors and some of the casualty’s crew boarded SEA EMPRESS between 0830 hrs and 1015 hrs. Main electrical power was restored, an assessment of the casualty’s condition was made and approximate calculations showed that 120,000 tonnes of cargo remained on board. However, the pump room was found to be flooded to sea level and more tanks found to be damaged, including the Fore Peak. Pumping out of the pump room was re-commenced and extra equipment was ordered from ashore to handle the additional damaged tanks.
Later on the Monday afternoon SEA EMPRESS refloated. The five tugs in attendance were unable to control her movements and she moved west across the main channel. At about 1715 hrs, the casualty was in line with the main exit from the ‘pool’, facing inwards and a request was made to those ashore (MFCU and Milford Haven Port Authority) for permission to take the casualty out to sea. Although this was agreed to, it was not fully communicated to those on board. However, to take the casualty to sea would require the use of her main engine but as it had not been prepared for use, the question was academic.
SEA EMPRESS was being swept towards Saint Ann’s Head where she grounded at about 1815 hrs. During the early evening efforts were made to introduce inert gas into damaged tanks but with the casualty’s hull generating sounds, suggesting that hull failure and a possible explosion might occur, all persons on board evacuated onto attending tugs by 2245 hrs.
Various options were again discussed by the salvors for the following day. It was decided that the damaged tanks should be sealed on deck at low water to create an air lock in each tank then at the following high water it was anticipated that the casualty would refloat. Once afloat she would be deliberately grounded south of the Angle Buoy, between the East and West Channels, in order to gain control of her.
Tuesday 20 February
Two further tugs, PORTGARTH and VIKINGBANK, arrived at Milford Haven at about 0600 hrs on Tuesday 20 February. Members of the salvage team re-boarded SEA EMPRESS, which was still aground off Saint Ann’s Head, at 0840 hrs to be joined later by some of the casualty’s crew. On several occasions during the following two hours grounding noises were heard throughout SEA EMPRESS and significant losses of oil were observed but the casualty’s own engineers prepared the main engine for use. Although the salvors continued to prepare tanks for refloating the casualty their preparations were not sufficiently advanced to allow them to pressurise the damaged cargo or ballast tanks at low water as they had originally intended.
SEA EMPRESS began to show signs of movement at 1645 hrs and the main engine was tested and found satisfactory. The salvors were given permission to bring SEA EMPRESS to Herbrandston Jetty if the refloating attempt proved successful.
Eight tugs were in place by this time and over the period to 1936 hrs various main engine and tug movements were made in attempts to refloat SEA EMPRESS. These efforts were unsuccessful. Some of the tugs which were pushing on the port side experienced difficulties due to the oil film on the hull of the casualty causing them to skid and to be unable to apply full power.
The salvors judged it would be imprudent to remain on board SEA EMPRESS overnight and all persons evacuated by 2245 hrs but three tugs remained in close attendance. Meetings were held late into the night and plans, produced by the salvors for the following day’s operations, were discussed by the concerned parties. It was again decided to increase the casualty’s buoyancy, and reduce her list, by pressurising the ballast tanks. The pressures to be used would be higher than for the previous attempt.
The tanker, TILLERMAN, was made available for lightening purposes after assurances to her managers from MPCU that any costs would be underwritten by HM Government.
Wednesday 21 February
Salvors, crew, and MPCU staff had all boarded SEA EMPRESS by 0815 hrs on Wednesday 21 February. The casualty’s position was estimated as being about 200 metres west of her position on Tuesday. Attempts to pump out the pump room were proving unsuccessful with flood water remaining at sea level.
As No 2 Port ballast tank was still intact, portable pumps were used to pump out this tank. Preparations were made to pressurise the damaged ballast tanks with compressed air in anticipation of low water. The Aft Peak was also pumped out. Cargo tanks were also pressurised with inert gas at normal system pressure. Shortly before low water at 1350 hrs it was observed that the rate of cargo leakage from the casualty had increased,
The tug ARILD VIKING had arrived during the previous evening and thirteen tugs were in position by 1630 hrs. Two pilots were on board and the line of on board command was set out for the anticipated refloating operation.
The bows of SEA EMPRESS started swinging to port, under the influence of the tugs, at 1735 hrs. Although the casualty’s main engine failed to start when requested it was eventually started, and subsequently operated, from the emergency controls. The casualty then floated free at 1800 hrs, was moved astern into the main channel and proceeded to the selected berth alongside Herbrandston Jetty on the north side of the Haven. First mooring lines were ashore at 2155 hrs.