Testimony of Dr Tom Hinks, HSE Expert Witness

Testimony of Dr Tom Hinks, HSE expert witness. (15th November 2001)

This is not a verbatim account; it was written up from detailed notes taken during the trial.

KEY: J = His Honour Judge Stokes

H = Dr Tom Hinks

P = Patrick O’ Connor Q.C.

W= Mr Walker Q.C.

P: Dr Hinks you are one of Her Majesty’s specialist inspectors of Health and Safety, specialising in mechanical engineering and you have a B.Sc. in mechanical engineering, an M.Sc. and a Ph.D. in applied mechanical engineering and also have 31 years experience in industry and have worked for the HSE since December 1990 as an inspector?

H: Yes.

P: You have many times investigated accidents and you are familiar with the safe use of lifting equipment?

H: Yes.

P: Would you describe the HSE as a prosecuting authority?

H: It is one of its functions.

P: What happens if somebody wishes to consult the HSE with regard to practice in the work place?

H: We take phone calls, we often advise, we often make visits to the work place. We support good working standards across the country.

P: On the 29th April 1998, you went to Euromin Ltd with Chris Barringer? H: Yes.

P: Were Roger Grant, Jim Harris, Sean Currey and various Liebherr staff also present?

H: Yes.

P: Was James Martell there? H: No.

P: The purpose of this visit was to inspect and investigate the circumstances of the incident, which led to the death of Simon Jones, to gather information and to find out what you could?

H: Yes.

P: Did you inspect the Liebherr 984?

H: Yes.

P: Had it been moved?

H: Yes.

P: Was the boom on the ground?

H: Probably, that would have been a safe position.

P: Did you inspect the stem of the grab and see the lifting hooks welded?

H: Yes.

P: Was it your information that chains were suspended from these hooks?

H: That’s how it was described to me.

P: Had you ever come across such an arrangement before?

H: Never.

P: If you were consulted by an employer about setting up such a system, or you saw one in use, what would be your response?

H: In the first instance, I would say on no account should this be done because of the inherent danger or risk; the employer should think again. In the second instance I would advise the relevant HSE inspector to issue a prohibition notice.

P: Which potential risks would concern you?

H: The integrity of the hooks including the parts to which they are attached, the safe working load, whether the chains were the right type and grade for the application. As the chains were going through the grab, you would need to consider the weight of the grab; the grab would need to be isolated from the hydraulics if used. It’s not like freely suspending a load from a hook where there is a large latitude for error. The grab may come in too low and hit obstacles or people. There is the possibility of the grab closing on the chains with a force of 13.3 tonnes; this would cause severe damage and could sever the chains.

P: Would your response be the same regardless of the length of the chains?

H: In many ways, yes. A longer chain gives more room, but otherwise the answers would be the same.

P: You are aware that it is normal for the excavator driver not to be able to see directly into the hold?

H: I was told about this; this is quite usual.

P: How is the risk affected by the lack of view?

H: You rely on other forms of communication by somebody else. You need a trained banksman with full knowledge of a code of signals. Both he and the driver must understand each other fully and must have consulted beforehand. Alternatively, you can use a walkie- talkie system.

P: If you expressed all these concerns but an employer said: “But I have a superb driver; I can trust him completely.” What would you say?

H: Does he know recognised signals? Is he fully conversant with their use? Is there somebody in overall control of the lifting operation? It is not the job of the crane driver to control the operation.

P: Did you inspect the controls in the cab and observe their sensitivity?

H: Yes. They were very sensitive.

P: Is this normal?

H: Yes, for ergonomic reasons.

P: If the employer said to you that the driver is such a good operator that he would never nudge the joystick; would you agree to the system?

H: No. With jackets etc on a cold day, you cannot guarantee that he won’t inadvertently operate the controls.

P: The Liebherr is a hydraulically operated machine; what happens if the hydraulics fail?

H: The grab closes.

P: With what force?

H: It would be the weight of the grab under gravity; there would be no power.

P: What would you say about the presence of workers within the range of the excavator arm?

WALKER –objection on grounds that this is simply opinion – objection over ruled as this is an expert witness.

H: You should endeavour to keep people outside the range of the excavator arm. In some cases you can’t, so I would expect method statements and risk analysis of procedures while the hooks and chains are above the ground. Persons should be kept well away until chains are at rest at ground or bag level.

J: If the chains are lowered on to the tops of the bags then the workers could approach but if the grab was too low, they should wait until it was raised to the correct position?

H: If the hooks had cleat plates, and you were using the proper lifting hook without the grab, the chains could be lowered onto the bags, when the chains were not swinging, the driver could stop the machine and the workers could fit the chains on the bags. The workers would then move back and the driver would lift.

J: What should happen if the hook comes into low and the chains are flopping around?

H: Before people access the area, the banksman signals to the driver to raise it again.

P: As to this system, which was being used, was there any way of operating it without the risks you have described?

H: Not to my knowledge.

P: Were there any markings on the joystick to show mode and direction?

H: No.

P: Should there be?

H: Yes.

P: According to what?

H: An Approved Code of Practice, the Docks Regulations and various British Standards.

P: As you understood the system at Euromin, did workers have to go under the jaws of the grab to do the job?

H: Yes, I was told the jaws were open.

P: What was the risk of something happening?

H: A foreseeable risk in my opinion.

P: What is the specific designed purpose of a clamshell grab?

H: To scoop up loose aggregate and to move it from one place to another.

P: Should there be any one near it?

H: With a safe method of working, no.

P: What is the maximum operating hydraulic pressure?
H: 300 atmospheres.

P: Is this equivalent to 4,500lb per square inch?
H: Yes.

P: In reaching your conclusions about the risks, you have borne in mind many statutory regulations and British Standards?

H: Yes and industry Approved Codes of Practice.

P: You obtained from the cab of the Liebherr an instruction manual, which you gave to Miss Barringer?

H: Yes

P: Where was it?

H: Behind the driver’s seat.

P: Because of concern that the manual we had as exhibit is not identical with that one, we are obtaining the original manual, which will be brought to court later today.

When you inspected the excavator, was the safe working load marked on the exterior?

H: Not that I could see.

P: Was it marked anywhere on the machine?

H: No.

P: Looking under tab 5, volume (a) photos 1 and 2 which were taken in March 2001, can you see marked under the open cab door: “SWL 6000Kg, including 2,500 Kg grab weight”?

H: Yes.

P: Should this marking be on the machine all the time?

H: Yes.

P: This is a statutory regulation?

H: It is.

P: Making a risk assessment and planning an operation might be thought complicated. Are there statutory duties for example to carry out risk assessments?

H: Yes.

P: Written assessments?

H: Normally.

P: So you start with a risk assessment, then you work out a safe system?

H: Yes.

P: There were ways of avoiding risks. Did you know that Euromin had the proper hook attachment?

H: Yes, I was told by Mr Vines.

P: If this hook had been used, would there still be risks involved?

H: This would eliminate the risks associated with the clamshell grab.

P: If there was a check valve, manually operated at the end of the excavator arm, which would isolate the grab and prevent it from closing, would this remove any of the risks you have identified?

W: Objection, this is not within the witness’ report.

JURY SENT OUT

11.40a.m. Jury returned.

P: If a check valve was used, would any risks remain?

H: The risk of the grab closing is removed; the other risks remain.

P: Can you explain better how the hook attachment can be used to lift multiple heavy bags?

H: You can be certain of the weight, you can use single or multi chains or web chains spread to suit the position of the bags.

P: The system that was in use at Euromin, was it appropriate?

H: I don’t think it is an appropriate system.

P: Why?

H: It gave the potential for persons to be put in a vulnerable position, with consequent risks to their health and safety.

W: (Began by repeating all of Mr O’Connor’s questions about qualifications and received the same answers)

W: In industry, what line were you in?

H: The design of special purpose machine tools.

W: You have been with the HSE since December 1990?

H: Yes.

W: You have investigated incidents arising from various activities?

H: Yes, with specific reference to mechanical engineering.

W: As to your experience of docks, have you seen a ship being unloaded?

H: Once or twice!

W: You made a statement on 6th March 2001, 3 years after the incident. Was this your first statement?

H: I made a draft statement before.

W: Was this based on your visit of the 29th April 1998 and on witness statements?

H: Yes.

W: The only Euromin staff you met on 29th April 1998 were Sean Currey, Jim Harris and Roger Grant?

H: Yes.

W: The Liebherr controls should be marked with directions?

H: Yes.

W: These weren’t marked?

H: Not that I could see.

W: So all the Liebherr excavators in the country are deficient?

H: There should be a diagram in the cab at least, a hard copy.

W: There was a diagram in the manual; you say it should have been in the cab?

H: Yes.

W: You are not saying this has anything to do with the “accident”?

H: I’m not saying that at all.

W: The marking of the safe working load is covered by which regulations?

H: Docks Regulations.

W: What, what’s that? I haven’t got them.

In the guidance notes for certificates of exemption at the top of page 194, it explains about being exempt from regulations.

H: Yes that’s what it says.

W: Can you say if the Liebherr needed to comply with construction lifting regulations or did they need to apply for a certificate of exemption?

H: This machine came within the scope of Docks Regulations.

You will find the relevant information in Appendix 9, “Docks Regulations”.

W: So construction lifting regulations didn’t apply?

H: No.

W: The shut off valve, how long before now did you know it existed?

H: Soon after the “accident”.

W: In his evidence, Jerry Vines told me that no check valves were fitted to the clamshell grab. That’s the opposite to what you have told the jury.

H: Not at all. I spoke to Jerry Vines just after our visit to Euromin; the valves were fitted to the end of the dipper arm.

W: Under divider 4 can you show me on the photograph where the shut off valves are?

H: They are where the flexible hydraulic hoses…..

J: The photograph under tab 3 is much better.

H: (Pointing to position on photograph) They were fitted somewhere up here – he was referring to the manually operated ball valves. This is totally different from a check valve.

W: The valve fitted was not a check valve?

H: No, not at all.

W: The check valves on the cylinders wouldn’t be any help?

H: It’s a failsafe system in a hydraulic circuit. There is no ambiguity; check valves and stop valves are different things for different purposes.

W: You realised the stop valves were there?

H: I understood from Jerry Vines that they were check valves.

W: You didn’t regard this valve as significant?

H: No. The overall system had inherent weaknesses; there was the potential for harm.

W: Assuming you knew the valve existed, at no point did you recommend the valve as a safety measure?

H: No, because it’s just for changing attachments.

W: In your report, you made recommendations; none of these involved the use of a stop valve?

H: No.

W: Using the lifting hook does not eliminate the risk of the excavator operator moving a lever and dropping the hook on somebody’s head?

H: No.

W: While the appliance is being operated people shouldn’t be under it?

H: Or within the confines around it.

W: While lifting or moving the hook or grab you would take precautions against any one getting near?

H: Yes.

W: People must go under it when it is stationary?
H: Yes. The banksman’s role is still crucial; he must understand unambiguously any signals from the hold and convey these to the excavator operator.

P: If the stop valve is turned to “stop” could the grab be closed by movement from the joystick?

H: No.

P: Everything else, including the dipper arm would be workable? H: Yes

P: If you were looking for a safe system of work, would you recommend the system as used at Euromin but with the valve turned to “stop”?

H: Not with the clamshell grab in place.

P: It would not be sufficient and safe practice?

H: The risks of the grab still remain apart from it closing.