Rank: Guest 
|
Posted By bluesail461
Hi,
As a CDM-C on a particular project I am required to comment on a design (from the US) for a frame which will have equipment located on platforms (3no) at a height of 4m. The whole frame is 9m in height. The platforms on which the equipment is located are fine, with hand and mid rails and toeboards and they are accessed by fixed vertical ladders. to gain access to the top of the frame (9m) a fixed ladder is used going up into the platform above through a trapdoor (as with a tower scaffold). Again these upper platforms are fitted with hand and mid rails and toeboards.
Only reason to access the frame would be for maintenance and cleaning purposes - It would not be an everyday occurrence.
Fall arrest options suggested to me are:
1. The US design has suggested the use of a retractable lanyard (10ft long) fitted to an overhead truss the length of the platform with a rope attached to the end of it for maintenance operatives to clip onto before ascending a ladder.
2.The client wants to specify loops on the fixed vertical ladders.
My thoughts are as follows. I dont like either of the suggestions above and would prefer a vertical fall-arrest cable fitted adjacent to each vertical ladder with the maintenance operative clipped on to a sliding device using a harness. There isnt the space to avoid the use of vertical ladders.
My questions are as follows:
1. Does my solution seem reasonable? Has anyone experience of using (and maintaining/inspecting) these vertical systems. Are they costly?
2. When on the platform at 4.5m and at 9m, even though it is fitted with handrails and toeboards do I still have to insist maintenance operatives are clipped onto the structure, as is the practice with MEWP's? My view is no as the work takes place ON the platform as opposed to a structure next to it but would like some feedback please.
3. Are hooped ladders a good idea - I have read research that states that their use as fall arrest should be avoided - I personally dont like them but not too sure about the legal situation with them.
Cheers
jez
|
|
|
|
|
|
Rank: Guest
|
Posted By Bob Youel
Firstly ask yourself 'is it my role to provide solutions or to comment on suggestions etc' noting the CDM regs; as you are not acting as the designer
From an initial look your idea seems good but only the client will make a decision. I would suggest that you make your client aware of differing ideas and leave it at that. Commenting in depth only on the proposals put in front of you
|
|
|
|
|
|
Rank: Guest
|
Posted By Edward H
OK lets take these seperately...
I think the maximum run allowed for a single vertical ladder is about 9m so you should be OK on that.
Ladder hoops do not work as fall arrest despite what it may say in the relevant BS. There is some research undertaken by HSE [search the research bit of their website] that confirms that, and indeed says that the hoops can actually increase the severity of injury. At best hoops provide some psychological support to the climber and give them something to lean back on and rest during a long climb.
There is also some HSE research that says that fall arrest systems don't work well inside ladder hoops; either the systems don't lock before the climber has been injured by smashing into a hoop or entanglement with the hoops can delay the fall arrest device "noticing" the fall allowing the climber to fall further than is safe.
To reduce the distance a climber will swing sideways if they do fall [and hence the risk of striking adjacent structure]. I would suggest you look at having either a fall arrest rail or cable system fitted up the centre of the ladder. This linked by a very short lanyard [300-400mm] to the chest attachment on a harness.
Speak to a reputable fall arrest supplier, they are getting a lot of experience at protecting fixed ladders thanks to wind turbines.
|
|
|
|
|
|
Rank: Guest
|
Posted By Dave Merchant For the situation you describe, IF USED IN THE UK, then an EN360 self-retracting lanyard (SRL) on a pulldown cord is the best solution by far, as it'll work with or without cages, needs very little operator training and maintenance, and doesn't require the ladder to be of any specific design capacity. You'll need to ensure the anchor point is rated to what the SRL instructions ask for (typically 15kN). The rules on ladder cages and fall arrest are different in the USA (and different between uses too - OSHA treats construction and maintenance as entirely separate problems), and US basic harnesses rarely have a sternal attachment point, which makes SRLs even more appropriate. Fixed wires and rails are the best choice for ladder runs over about 15m, below that SRLs win hands down unless there's a specific concern about abuse (vandalism on public structures, etc.) or corrosion (offshore platforms, chemical plants, etc.) You can get a copy of our fixed ladders article from HSW March 08 via this link: http://www.lexisurl.com/FIXEDLADDERS
|
|
|
|
|
|
Rank: Guest
|
|
|
|
|
|
|
Rank: Guest
|
Posted By Kelly Hughes
You need to check out BS5395 Part3 Code of practice for the design of industrial type stairs, permanent ladders and walkways.
Section 6 covers Fixed Ladders.
It also states that
"except on chimneys, the height of the ladder should not exceed 6 meters without an intermediate landing, preferably breaking the line of the ladder".
|
|
|
|
|
|
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.