Summary of Events

All times in this report reflect Zulu, a military standard time reference system that is based on the global time zone division commonly referred to as the Greenwich Mean Time (GMT) reference system.

1. At approximately 1030 on the morning of 5 October 2004 the lookout coming off watch on the bridge of HMCS Chicoutimi discovered a loose brass nut on the upper lid vent in the conning tower as he came below.  The discovery of this nut would be the first step in a chain of events that significantly altered the course of events in the submarine and would test the training and professional abilities of every member of the crew.  Although several people unwittingly contributed to the chain of events, no one aboard the submarine or ashore could have known of the sequence of events about to unfold and no one can be held personally responsible for the outcome: serious fires in the CO’s Cabin and the Electrical Space, a fire in an oxygen generator, nine casualties, and the tragic death of Lieutenant(N) Chris Saunders. 

Reactivation of HMS Upholder

2. The Canadian Government signed a contract for the acquisition of the four  Upholder Class submarines from the Government of the United Kingdom.  The submarines had been taken out of service shortly after construction when the Royal Navy decided to only operate nuclear powered submarines.

3. The reactivation process entailed a system-by-system examination of the submarine, utilizing the planned maintenance schedules to determine the best approach in each case.  The UK Ministry of Defence entered into a contract with BAE Systems in Barrow-in-Furness to conduct the reactivation work package on the four submarines.  Although the first of the class built, it was decided that Upholder would be the last submarine reactivated.  Over a period of several years the submarine underwent extensive work on the multitude of onboard systems.  In some cases the process focussed mainly on system checks while in other cases the process entailed extensive overhauling of equipment. 

4. As with most contracts of this magnitude there were points of contention.  The representatives of the Canadian Government wanted to acquire the greatest possible capability while the Ministry of Defence needed to provide the capability it had contracted for, and not build a de facto new submarine for Canada with greater capability than had been built into the Upholder Class. What was not contentious was the requirement to make the submarine in all respects seaworthy and safe for operations.  After extensive work the submarine was reactivated in accordance with the contract and was deemed by all parties to be ready for sea.

Canadian Acceptance

5.HMCS Chicoutimi was accepted by the Government of Canada on 2 October after a renaming ceremony that changed the name of the submarine from HMS Upholder to HMCS Chicoutimi.  This was the fourth Victoria Class submarine to be taken over by Canada and the fourth boat to be making the voyage to Halifax, Nova Scotia. 

Departure for Canada

6. After completing sea checks, the submarine departed Faslane, Scotland at 1000 on 4 October and was expected to arrive in Halifax on 18 October.  For operational reasons the submarine operating authority could not provide dived water for the first portion of the transit.  This would keep the submarine on the surface until the afternoon of 5 October.  The lack of dived water would force the submarine to sail into a low-pressure system that was generating gale force winds and building significant seas.  Except for the weather, the submarine’s first day at sea was uneventful. 

First Water Ingress

7. At approximately 0300 on the morning of 5 October the time had come to rotate the officer of the watch on the bridge as per the normal rotation.  The relieving Officer of the Watch proceeded to the bridge to receive the handover.  While both officers were on the bridge the conning tower upper lid remained open and the lower lid was shut.  This is defined as tower reversed and is normal procedure for this situation.  While reversed some water accumulated within the conning tower due to the heavy seas.  Once the handover was complete, the officer coming off watch proceeded into the tower and shut the upper lid.  The officer on the bridge then ordered the tower drained down to remove the accumulated water and the lower lid opened to allow the officer in the tower to enter the submarine.  When the Control Room staff attempted to drain down the tower they were unable to do so.  After attempting to drain down the tower for several minutes it was finally decided to open the lower lid and allow the residual water in the tower to enter the Control Room.  It was determined that the cause of the problem was a hydraulic restrictor valve that limited the movement of the drain valve.  The exact amount of water that flowed into the submarine is unknown; however, most of the water was caught in the catch basin at the base of the tower.  Inside that catch basin is a non-watertight hatch that was designed                                                                                                                                  Some water leaked around the hatch down onto 2 Deck.  The crewmembers on 2 Deck responded quickly and cleaned up all the water before any damage could be done.  Several of the crew involved in cleaning up reported an electrical smell in the area.  The Marine Systems Engineering Officer was informed and a search was conducted.  The smell quickly dissipated and the source was not located.  The Senior Electrician also carried out a survey of the electrical systems and found no defects. This incident is unrelated to the events that would unfold later that day.

Tower Defect

8. The defect in the tower vent mentioned at the beginning of this sequence of events was reported mid-morning on 5 October.  There had previously been a problem with the vent during the early days of the sea trials, and BAE Systems had repaired the vent to the satisfaction of the MOD and the crew.  The vent had also successfully passed the vacuum test conducted as part of the pre-sea checks.

9. Given the intention to dive the submarine within a few hours, repairing the upper lid vent was very important.  A repair party consisting of two Marine Engineering Technicians gathered their tools and assembled in the Control Room.  In order to repair the vent the upper lid would have to be left opened.  Two options presented themselves at this point, either leave both lids open and run the submarine opened up or shut the technicians out of the submarine by shutting the lower lid while they affected repairs to the vent.  After considering all of the factors involved, the Commanding Officer ordered the main engines shutdown, therefore propelling the submarine via the main batteries, and ordered the tower to be opened up at 1052.

Second Water Ingress

10. After working on the vent for approximately 25 minutes, one of the repair party proceeded below to get another tool.  Just as he was transiting through the conning tower, a wave hit the submarine causing water to well-up in the fin over the level of the conning tower upper lid, resulting in a significant ingress of water into the submarine.  The exact amount of water is unknown; however, based on testimony received it is believed to have been approximately 2,000 litres. 

11. In this particular case, the catch basin at the base of the tower was insufficient in size to contain the water and it overflowed into the Control Room.  Reports received indicate that water in the Control Room was over the toes of people’s boots and that it was sloshing from side to side.  One description of the subsequent clean up effort that reveals the magnitude of the ingress states that taking five large buckets of water out of the Captain's Cabin had no appreciable impact on the volume it contained.

12. All off watch hands were required to help clean up the water.  The water was cleaned up over the subsequent 45 minutes by transferring most of it into the mast well and then pumping it overboard.

VP Earth

13. Shortly after this water ingress the Motor Room reported a VP Earth.  The magnitude of the earth was full battery voltage.  Based on advice from the Marine Systems Engineering Officer the CO decided to close up Damage Control Headquarters to facilitate the isolation of the equipment affected. 

14. The process of isolating the VP earth was executed in accordance with laid down procedures.  Initially, each of the DC load centres was isolated in turn.  Then the two DC load centres were switched off.  The batteries were then isolated one at a time. None of these steps isolated the VP Earth.  This meant the problem was in either the main propulsion switchboard or in the main power cables.

15. As consideration was being given to the next step in the process, a pipe was made indicating electrical explosions in the Control Room.  This pipe was quickly followed by a pipe of fire in the Captain’s Cabin.  Damage Control Headquarters quickly shifted focus from an electrical problem to a fire onboard the submarine. 

Fire

16. Shortly after 1315 on 5 October, the submarine was transiting on the surface when popping noises were heard in the Control Room and a fire broke out in the Captain's Cabin.  The fire spread rapidly through what would later be determined to be two holes blown through the deck into the Electrical Space.  Both the Control Room and 2 Deck completely filled with thick black smoke in a matter of seconds.  Everyone in the vicinity was immediately ordered into emergency breathing masks.  Those that could not immediately don a mask either evacuated the area or were incapacitated by smoke.  Within a few minutes the entire crew would be on emergency air and would remain so for the next three hours.

17. The initial crew response to the fire was executed in accordance with Emergency Operating Procedures.  Several people attacked the fire in the Captain’s cabin and in the Electrical Space below.  The quick reaction by the crew ensured that the fires were rapidly contained. 

18. It was quickly determined that the crew was dealing with an electrical fire; therefore, the main and auxiliary power breakers were opened, cutting off all power to the submarine.  This assisted the crew with the firefighting, but left the boat without any electricity or propulsion.  Isolating main power also eliminated the ability to recharge other key systems, including hydraulics and high-pressure air.

19. The CO ordered the after auxiliary power breaker remade in an attempt to use the low-pressure blower to remove some of the smoke in the Control Room.  Shortly after the breaker was remade, another report of fire was heard in the Motor Room and the breaker was opened once again.  It was decided that no breakers would be re-energized until detailed checks could be completed on the cabling running to the various pieces of equipment to ensure that the fire had not affected them.  It was never determined if the second fire reported was caused by the making of the auxiliary power breaker or if it was caused by a residual A class fire. 

20. What ensued was a lengthy process of attacking and overhauling the fire and of removing the smoke from the submarine without the benefit of the fitted ventilation systems, which had been rendered inoperative through the loss of main power.  The de-smoking was completed after significant effort by the Engineering Department to start a main engine without the electrical control circuitry.

Casualties

21. As a result of the fire in the Captain’s Cabin nine casualties suffered smoke inhalation.  Of these nine casualties, six were able to return to duty within a few days while the three more seriously injured remained under the care of the Physician's Assistant.  It was determined that the three remaining casualties needed to be evacuated as soon as conditions would permit the transfer.

Fire in the Oxygen Generator

22. At approximately 1910 on 5 October a second fire occurred in one of the forward oxygen generators of the submarine.  The generators were in use to improve the air quality in the submarine.  Emergency Operating Procedures for an oxygen generator fire were undertaken.  The fire was put out within two minutes and was reported out at 1912.

Recovery Efforts

23. Shortly after the fire, the submarine reported the incident to authorities both in England and in Maritime Forces Atlantic Headquarters.  The operating authority in England immediately dispatched a Maritime Patrol aircraft to go to the submarine and started a significant operation to deploy other units and assets to assist the stricken vessel.

24. HMS Montrose, a Royal Navy frigate, was dispatched and arrived on the scene at 1128 on 6 October to render assistance.  At 1330, despite heavy seas, HMS Montrose sent over a doctor and a physician's assistant to help with the casualties.  The transfer was completed with great difficulty, the passengers having to leap through the fin door as the small boat they were in rose to the crest of a wave.  The doctor came onboard HMCS Chicoutimi and immediately assumed responsibility for the patients.  After further assessment and some initial treatment, the doctor reaffirmed the need to evacuate three patients as soon as possible. 

Evacuation of Casualties

25. Despite heavy seas and poor conditions a Royal Navy Sea King helicopter conducted a medical evacuation.  Three casualties were extracted from the bridge of the submarine.  Once in the helicopter, it was immediately determined that the most critically injured casualty, Lieutenant(N) Chris Saunders, required urgent medical care.  The Sea King was therefore diverted to Sligo, Ireland. Sadly, Lieutenant(N) Saunders was declared dead shortly after arriving at the hospital in Sligo.

Restoration of Systems

26. Over the four days that followed the crew of the submarine restored some electrical power and other key systems through a methodical approach to system-by-system restoration.  Within 50 hours of the fire in the CO’s Cabin the material state of the submarine had substantially improved.  The atmosphere was breathable; the low-pressure blower was available for maintenance of buoyancy; the HP Air compressors, hydraulic pumps and the firefighting systems were available; and preparations were being made to tow the submarine.

27. A man overboard did occur during the preparations for towing the submarine.  The crewmember in question was secured to the casing with a safety line when he was washed overboard.  Although the safety line prevented him from being swept away from the submarine, it also kept him tethered to the vessel as it rolled from side to side, dragging him underwater in the process.  A quick thinking diver in the safety boat swam to his rescue and cut his safety line. He was transferred to HMS Montrose where he was checked by medical staff. He was deemed fit to return to duty but remained onboard the ship overnight.

28. The submarine was taken under tow on 7 October by Anglian Prince.  On 9 October the tow was transferred to the MV Carolyn Chouest.  HMCS Chicoutimi returned to Faslane, Scotland on 10 October.