3 A comprehensive Agreed Statement of Facts was tendered:
2. At all material times, particularly on 20 April 1999 , the defendant, amongst other things, carried on the business of fabrication of steel at its Newcastle Steel Plant in the state of New South Wales .
3. The Steel Works Power Plant formed part of the said Steel Plant of the defendant's business.
4. Located in the said Power Plant was the No. 3 boiler.
5. The said No. 3 boiler was a conventional gas-fired water tube boiler of 50 tonnes per hour steam capacity.
6. The said No. 3 boiler formed part of a bank of four similar boilers which generated high pressure steam for use in a series of steam turbines in the defendant's business.
7. The said No. 3 boiler featured seven gas burners. Five of these burners were supplied with Blast Furnace Gas - a low calorific value waste gas. The other two burners were fired with Coke Oven Gas - which gas was used to supply a number of flare lances for start up purposes.
8. Blast Furnace Gas was supplied to the said No. 3 boiler through a large diameter main, through a butterfly valve, a U type water seal, a control valve and a burner valve.
9. Coke Oven Gas was supplied to the said No. 3 boiler through a valve number PCOG 3.130 (" Valve A "), a water seal type valve (known as a GAKO valve), a control valve and a burner valve.
10. A single forced draft fan supplied combustion air to the said No. 3 boiler.
11. The heated combustion air was supplied to each Blast Furnace Gas and Coke Oven Gas burner through individual shut-off valves.
12. In addition, flow control valves were used to control the gas-air ratio on the Blast Furnace Gas burners.
13. Flue gases from the boilers were extracted by one or two induced fans which directed the cooled flue gases towards the stack.
14. On or about 17 December 1998 the defendant issued a Standard Operating Procedure ( SOP ) in respect of the emergency shutdown of the boiler gas systems at boilers 1 to 4 (SOP 05.01E.08).
15. The purpose of this SOP was to provide instructions to operational staff for the emergency shutdown of boiler gas systems where there was, amongst other things, a loss of flame and/or loss of the forced draft fan.
16. The SOP mandated the particular procedure to be followed in the case of such loss.
17. On 20 April 1999 the said No. 3 boiler tripped due to an electrical fault with the forced draft fan. This was caused by a blown fuse.
18. An investigation conducted by the defendant, at that time, disclosed that the forced draft fan was not running. Further, no spare fuses were able to be found.
19. As a result of the forced draft fan tripping, all the burners to the said No. 3 boiler also tripped.
20. Mr Neville Forster and Mr Darren Cannon, two employees of the defendant who were working day shift, attempted to restart the boiler.
21. Following this Mr Cannon started to run water into the Blast Furnace Gas U seal.
22. A decision was made by Mr Robin Pickles, an employee of the defendant and shift Foreman of the Power Department of the defendant, to leave the said No. 3 boiler off until the next day shift.
23. At about 6.30pm there was a changeover of shifts between the day and night shift.
24. Mr Rodney Fitzclarence and Mr Donald Heggs, employees of the defendant, commenced duties on the night shift. Mr Gary Cooper, an employee of the defendant, commenced duty as night Shift Foreman.
25. Mr Cooper discussed the issue of what was happening with the said No. 3 boiler with Mr Pickles at changeover. Mr Cooper was told by Mr Pickles that the forced draft fan on the said No. 3 boiler was not operational and that the said boiler had been fully closed down.
26. Following commencement of his duties, Mr Heggs watched the operation of boilers numbered 1, 2, 4 and 6.
27. Mr Heggs also ensured that the said No. 3 boiler was safe whilst Mr Fitzclarence was preparing to purge the gas lines on the said boiler.
28. At approximately 7.00pm Mr Fitzclarence changed the purging system from steam to nitrogen and commenced purging the Blast Furnace Gas line.
29. It took Mr Fitzclarence approximately one hour to carry out this function.
30. Mr Fitzclarence then closed the Coke Oven Gas isolating valve number PCOG 3.130 on the said No. 3 boiler.
31. At approximately 8.45pm Mr Fitzclarence commenced purging the Coke Oven Gas line. In doing so he lit two hand flares.
32. The SOP used by Mr Fitzclarence to purge the Coke Oven Gas line was SOP 05.OIC.17 which related to the purging of Coke Oven Gas from the isolating valve to the boiler burner valves. This was not the appropriate SOP to be implemented as it was a precondition for the use of this SOP that the boiler fans be in operation.
33. After Valve A there are 3 additional valves or components which would if closed prevent the Coke Oven Gas from going to the boiler. There was in place throughout the main line a series of devices which had the aim of preventing the uncontrolled flow of Coke Oven Gas to the boiler. At the time of the incident Valve A was not sealing properly.
34. The defendant was aware that Valve A to the said No. 3 boiler was not sealing properly and had been leaking for some time.
35. The GAKO valve was fitted with a safety interlock device that should have prevented the opening of the GAKO valve in circumstances where the FD fan was not operating. There is evidence that the GAKO valve was partially opened manually by the day shift operators on 20 April 1999. This had not been identified as a fault by these operators.
36. Also, the forced draft fan was not operating. This fan provided combustion air to each of the Blast Furnace Gas and Coke Oven Gas burners.
37. The mixture of fuel gas and air can and, upon reaching a combustible level, will ignite.
38. At approximately 9.20pm the said No. 3 boiler exploded because of the build up of gases in the boiler.
39. The source of ignition of the gases in the said No. 3 boiler was either the heat from the boiler or the hand flares or some other source of ignition.
40. The explosion damaged the switch room which in turn shut down the other boilers. All steam generation is lost in this circumstance. An absence of steam causes the shutdown of the generators, the blowers to the blast furnaces, the works air system and the coke oven exhausts which has a flow on effect. The entire steelworks were shutdown as crucial plant had been affected.
41. At the time that the said No. 3 boiler exploded both Mr Fitzclarence and Mr Heggs were in the boiler building in the vicinity of the said boiler.
42. From the explosion neither Mr Fitzclarence or Mr Heggs suffered any injury. However, they were placed at risk of being seriously injured.