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vinod  
#1 Posted : 02 March 2014 06:54:19(UTC)
Rank: Forum user
vinod

I have got some aluminum mobile scaffolds of 12 meter height (size- 1.5 meter X 2.5 meter) and have used outriggers (04 nos at each sides) to support this structure. Initially the scaffold was erected for a single platform concept with 240 kgs SWL. But now due to the workplace demand, the contractor has proposed for having multiple platforms at every 2 mtr height difference on the same structure with a load capacity of 540 kgs and they have support from their local vendor. My question is, up to what height a mobile aluminum scaffold is safe to use and such above mentioned alteration are allowed & safe?. I have seen no markings on the structural components nor the caster wheel they used in this scaffold. I appreciate if anyone could advise me with some guidelines especially on mobile aluminum scaffold erection and usage?
RP  
#2 Posted : 02 March 2014 07:29:45(UTC)
Rank: Forum user
RP

Including the use of the outriggers to increase the height to base ratio, indoors 3.5 to 1 and outdoors 3 to 1 this is to the platform height only and assumes that the outriggers are placed correctly.
vinod  
#3 Posted : 02 March 2014 07:40:18(UTC)
Rank: Forum user
vinod

Thanks RP, could you let me know by referring which standard or guideline, i would get more info about mobile aluminum scaffolds, especially its base ratio, permissible height etc..
Finn141257  
#4 Posted : 02 March 2014 08:01:13(UTC)
Rank: New forum user
Finn141257

Vinod I would recommend you refer to the PASMA website http://www.pasma.co.uk/ PASMA are now active within the Middle East and are recognised as authority on mobile towers and also you would do well to refer to AD EHSMS Code of Practice 26.0 "Scaffolding" available at http://www.oshad.ae/en/pages/home.aspx perhaps one of the questions you need to ask though "Is a mobile tower appropriate for this particular task?" it seems quite high to me and wonder why you would need to move it on a regular basis? Perhaps static scaffold may be more appropriate?
Darach  
#5 Posted : 02 March 2014 09:03:10(UTC)
Rank: Forum user
Darach

Hi, I have been a scaffolder for over ten years and I would not erect an aluminium mobile scaffold @ 12m in height! Anything of this scale should be designed and erected by a competent advanced scaffolder, and preferably not aluminium. With alu scaff, always refer to the manufacturers specs, but if unsure, use the 3:1 smallest base to height ratio. If it is designed, fare enough. I have built mobiles 12 meters high out of tube and fitting, but this causes issues with moving 'the mobile' but if built correctly there is no risk surrounding stability. Like Finn says...why scaffold? Regards, Darach
stevedm  
#6 Posted : 10 September 2025 16:30:02(UTC)
Rank: Super forum user
stevedm

  • A mobile aluminium scaffold with a 1.5 × 2.5 m base can be safe up to 12 m only if certified to EN 1004 and erected exactly per manufacturer’s instructions.
  • Your current tower has no markings and is being altered beyond its original design load = unsafe and not compliant.
  • Multiple loaded platforms (540 kg total) should only be used if explicitly approved by the manufacturer and verified by a competent person.

 

peter gotch  
#7 Posted : 10 September 2025 16:38:08(UTC)
Rank: Super forum user
peter gotch

Hi Steve

You might have missed that the presumed bot called "leoli" has resurrected a thread from 2014.

Date of birth 1903 (I don't know why that is the default!). Joined Forums September 2025. One post. SPAM.

leoli REPORTED.

Edited by user 11 September 2025 13:42:38(UTC)  | Reason: Typo

thanks 1 user thanked peter gotch for this useful post.
Roundtuit on 10/09/2025(UTC)
Roundtuit  
#8 Posted : 10 September 2025 18:30:28(UTC)
Rank: Super forum user
Roundtuit

Probably time to abandon the concept of users listing web pages and blogs give their abuse for advertising

Roundtuit  
#9 Posted : 10 September 2025 18:30:28(UTC)
Rank: Super forum user
Roundtuit

Probably time to abandon the concept of users listing web pages and blogs give their abuse for advertising

stevedm  
#10 Posted : 11 September 2025 13:22:05(UTC)
Rank: Super forum user
stevedm

Originally Posted by: peter gotch Go to Quoted Post

Hi Steve

You might have missed that the presumed bot called "leoli" has resurrected a thread from 2015.

Date of birth 1903 (I don't know why that is the default!). Joined Forums September 2025. One post. SPAM.

leoli REPORTED.

Thanks Peter missed that bit...  trying to be too helpful...

thanks 1 user thanked stevedm for this useful post.
peter gotch on 11/09/2025(UTC)
Engr. Jerome Sancho Cruz  
#11 Posted : 25 September 2025 20:22:12(UTC)
Rank: New forum user
Engr. Jerome Sancho Cruz

Here are some trivia facts about the unique and strict requirements for mobile aluminum scaffolds (tower scaffolds) in the high-hazard environment of the oil and gas industry:

Stability & Safety Ratios

  • The Moving Rule: When workers are allowed to remain on a mobile scaffold while it's being relocated (a rare and restricted event in oil & gas), the maximum height to least base dimension ratio must be a very strict 2:1 or less (OSHA requirement). If a scaffold is 5 feet wide, its maximum height is only 10 feet.
  • The Static Rule: When the scaffold is stationary and locked, the maximum unrestrained height-to-base ratio is generally 4:1 (OSHA standard). However, many site-specific safety plans in the industry impose a stricter 3:1 or 3.5:1 ratio for outdoor use to account for wind and dynamic rig movement.
  • The Castor Wheel Lock: Mobile scaffolds must have positive wheel and swivel locks on all castor wheels. If just the wheel is locked but the swivel is loose, the scaffold can still be "kicked" or rotated off its base, which could cause tipping

Material and Environmental Hazards

  • The Sal[expletive deleted]er Threat: Despite being corrosion-resistant compared to steel, aluminum on an offshore rig faces a unique danger: Galvanic Corrosion. If aluminum scaffold components are connected to steel parts (like couplers or the structure itself) in the presence of sal[expletive deleted]er, the corrosion process is significantly accelerated, potentially compromising the scaffold's integrity.

  • The 6-Month Dismantle: A common requirement dictates that scaffolds containing aluminum tubes or beams should not be allowed to stand for more than 6 months without being dismantled, inspected for internal corrosion (which is often hidden), and re-erected.

  • The No-Riding Rule: It is almost universally forbidden for workers or materials to remain on an aluminum mobile scaffold while it is being moved on a rig or plant. If movement is required, the scaffold must be pushed only from the base (no higher than 5 feet above the surface) after all personnel are removed.

peter gotch  
#12 Posted : 26 September 2025 15:47:55(UTC)
Rank: Super forum user
peter gotch

Hi Jerome

You have written "expletive deleted" and I am going to avoid needing to write the same.

Nevertheless you have quoted from the BS textbook that is so prevalent in the O&G and broader extractive industries. 

H&S speak is full of abbreviations and acronyms that OSH professionals sometimes seem to assume that everyone else should be familiar with.

The Forum Rules prohibit me from spelling out one interpretation of BS so I will avoid that, but instead translate it as Behavioral Safety (making no apology for the English US spelling as BS took root in the USA).

In the USA they have OSHA Regulations which are usually nice and simple as they tell you what to DO (prescription) or what NOT TO DO (proscription).

Whereas in the UK and geographies where legislation is built on the British model, we go for the "goal setting" approach so that duties are qualified by words such as "so far as reasonably practicable".

Whilst it is quite difficult to benchmark OSH perfomance in different countries, often as the rules as to what to count or not vary very susbstantially it is very clear that occupational accident rates in the US are MUCH, MUCH higher in the US than in the UK.

So, in the absence of any other credible explanation it appears that the goal setting approach has been a greater success than the prescription and proscription that comes with being in a geography where e.g. OSHA Regulations are the law or have been adopted by some organisations where there is not that much law to work with e.g. in the Middle East.

The O&G and other extractive industries have proved time and time again that they appear to have little ability to learn from the past whether at individual corporation level OR as sectors as a whole and so similar things happen again and again.

...and I suggest that much of this can be blamed on BS, with more focus usually being given to unsafe ACTS than unsafe CONDITIONS partly as a result of misinterpretion (whether deliberately or not( of the findings of Henirich in 1931, Bird in 1969 and others.

In another thread you suggest that "fatigue" might be a "root cause" of something going wrong. It would be VERY rare than fatigue was ACTUALLY a root cause but easy to identify it as such in an investigation that does not deep nearly far enough to look for the underlying causes, usually being management failings which some may be uncomfortable about unearthing.

Suppose a worker falls when a corroded floor grid on a walkway gives way, it is very easy to conclude that the reason for the fall was that the worker was not properly "tied on" and not bother to ask why the floor and each grid had not been maintained as that means asking why management didn't have an effective preventive maintenance programme in place. 

Have you read e.g. the "Telos report" that BP Texas City commissioned and received before their plant went bang in 2005, killing 15 and injuring about 200? 

NOT the first time and not the last time that BP would have just celebrated best company OSHA numbers at a site which would then become the scene of a disaster.

....or the reports on the tailing dams failures first at Fundao, then a few years later at Brumadinho? In statistical terms from an H&S perspective Fundao only killed 19 (the environmental impact was huge) whereas nearly 300 died at Brumadinho? Do you think that multinational Vale whose Sustainability Reports have majored on their apparently good OSHA metrics learned from Fundao before something very similar happened again.

As for mobile towers, most users of these Forums live in geographies which work to "goal setting" standards and the prescriptive and proscriptive OSHA standards you quote do not apply even if some of the principles do but with different numbers when it comes to recommended thresholds for this or that. 

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