Fires involving hydraulic passenger lifts

[kurnal]

A project to build a new 2 storey  small assembly building incorporates a hydraulic passenger lift within the protected staircase. The lift has no motor room, the oil reservoir and pump are within one side of the shaft itself. The designer has asked me to help as the building inspector has raised concerns over the presence of a fire loading within the protected route.

My risk assessment and submission under Reg 16B will consider the characteristics of the oil, the probability that a release may occur and the release characteristics, the likelihood that this will ignite and the consequences of fluid combustion including the resulting temperatures, smoke obscuration and toxic gas concentrations.

Apart from the Kaprun disaster is anyone aware of other serious fires that have occurred involving hydraulic oil and lift installations ? Or had any similar issues raised by Building Control?

  

[Fishy]

I participated on a risk assessment on this back in 2002.  My recollection of the conclusions:

1.   There is a fire hazard associated with the release of hydraulic fluid under pressure, particularly if the leak is small enough to result in an aerosol suspension of the fluid.  That such aerosol suspensions could be ignited by a spark caused by switching of the equipment in the pump-room was reasonably forseeable;
2.   The consequences of any resulting fire could be serious (resulting in death or major injury);
3.   The likelihood of this event was concluded to be ‘very low’; no evidence of such an occurrence causing a fire was identified;
4.   Suppression would not reduce the risk of a fire occurring (but may make the consequences slightly less severe);

Practicable mitigation measures included:

1.   Use IP55 rated (or better) electrical equipment in these rooms wherever practicable;
2.   Doors/vents etc should be located so that they do not open onto escape routes (wherever practicable);
3.   use hydraulic fluids with low flammability (Quintolubric did a synthetic product which we found suitable).

Fishy

[kurnal]

Anyone help with this please?
The lift project in this thread relies on the lift landing doors to provide the fire protection to the lift shaft as it penetrates the floors of the building. In this case it is particularly important that the shaft is protected as the hydraulic plant is in the base of the shaft, therefore all doors have been uprated to the full duration of the portected shaft.  
The lift installers say its fully compliant with BSEN 81.
In looking at BSEN 81 (all parts) I cannot find any requirement for the lift shaft doors to close on failure of the power supply. The lift doors are motor driven to both open and close the doors.

If a fire causes a failure of the supply then the doors may remain open breaching the protection to the shaft. If that fire was in the hydraulic plant at the base of the shaft this could have serious consequences. The suppliers say they have installed these throughout Europe without any problem being raised before.

Am I overlooking  something?

[nearlythere]

Anyone help with this please?
The lift project in this thread relies on the lift landing doors to provide the fire protection to the lift shaft as it penetrates the floors of the building. In this case it is particularly important that the shaft is protected as the hydraulic plant is in the base of the shaft, therefore all doors have been uprated to the full duration of the portected shaft.  
The lift installers say its fully compliant with BSEN 81.
In looking at BSEN 81 (all parts) I cannot find any requirement for the lift shaft doors to close on failure of the power supply. The lift doors are motor driven to both open and close the doors.

If a fire causes a failure of the supply then the doors may remain open breaching the protection to the shaft. If that fire was in the hydraulic plant at the base of the shaft this could have serious consequences. The suppliers say they have installed these throughout Europe without any problem being raised before.

Am I overlooking  something?

Single stairway enclosure situation?

[Midland Retty]

Kurnal

I haven't got a copy of the applicable BS to hand to check myself, but your RA has correctly in my opinion determined that the lift doors must fail-safe in the closed position in the event of fire.

Regardless of what the BS does or does not say you have assessed the building, you have determined what is required. So will your client ask their lift contractor to ensure the doors are configured to fail-safe in the closed position? Will he they take heed of your advice? Will they not accept other solutions such as lobbying the lift?

Thats probably not the answer you wanted but I certainly dont think you are being overburdensome in your assessment of the scenario.

[Mushy]

Lobby protection at the base?

edit :sorry didn't see midlands reply

[kurnal]

NT no, whilst there are a couple of rooms opening off the landing there are alternative routes to another staircase fromthe landing and thse are within the single dirtection travel distances so I am not too worried about this.

MF Thanks, no I dont mind what advice I give them provided it is right and proportional. Have been thinking about it further since my last posting and am trying to quantify the time duration and circumstances that the doors will be open and identify what is happening with the hydraulics at the time the doors are open.  

Mushy- no room for a lobby at the base without a design change.

I have been telling them all along that its barking not to use oils of very low flammability in these installations and I think I am gradually wearing them down.

[kurnal]

It appears to be becoming common practice for the power plants of hydraulic lifts to be installed in the base of the lift shaft itself. But there seems to be an absence of Fire Safety related guidance or standards.

BS EN 81-3:2000+A1:2008- para 1.3F- "Fire propagation is not dealt with in this standard".

BS EN 81-73:2005 Scope- "This standard does not apply to a fire in the well".

BS EN 81-1 and 2 do not appear make reference to the likelihood or consequences of a fire in lift machinery sited  in the lift well.

Is there a need for further guidance on this?

[Midland Retty]

I would say so - it would appear the fire safety angle has been overlooked.

[Fishy]

Lift doors are (in my experience) never fire-resistance tested from the shaft side - they are fire-resisting from the landing side only (the theory being, I believe, that if you stop the fire getting into the shaft, which in a traditional lift installation has a reasonably low fire load, you don't need to stop it getting out of the shaft).  They also leak smoke like a sieve.  If you can get the fire test report(s) from the doorset suppliers they'll tell you whether they were tested from the shaft side or not.

So, I'd be surprised if you've got effective fire-resisting separation between the inside of the shaft and the outside, whether the doors are closed or not, and you certainly will not have smoke separation.