Posted By Dave Merchant
Although the physiological ergonomics of ladder climbing is very well studied (it's one of the standard fatigue tests used in medicine, so everything from energy consumption to the torque on wrist joints has been measured) there are AFAIK no studies into the specific issue of incremental fatigue from tall ladders, or how that fatigue would impact on things like safety, balance, concentration, etc. - plus the people climbing WTGs don't fit the standard models as they're fitness-adapted to the task.

In the UK the only industry sectors which have long-established "policies" on climbing ladders are telecoms and utilities (linesmen etc). What that policy *is* varies pretty much randomly, from a set maximum distance climbed per day to "stop if you're tired, mate". I've not heard of a UK claim for stress-induced injury specifically from climbing fixed ladders, only from falling off them.

Email me if you want ergo numbers & stuff.

Posted By Ben Hughes
Yeah, it depends on the type of tower but they can be 80m+ straight vertical ladders internally in our towers. As you mention, we do provide rest platforms at 9m intervals, and there are what we call tower-tower sections were, if the technicians want/need to, they can get off to rest. We also have rescue procedures, training etc etc so 'legally' we are OK but we dont think this is enough and its a big concern at the long term effects of daily climbing.

Hence we try and encourage the client to purchase elavators, this is not always possible as at the moment the HSE havent implemented this as a rule - i think they will eventually but in the mean time we need something else. We're using climb assistants, but need to sell these to the clients...therefore if I can get hold of scientific evidence for our sales dept it may 'encourage' more clients to chose the climb assistants as opposed to free climbing.

Posted By Della Pearlman
I had a bit of free time so here are some more articles - one or two are free access, and you can buy the others online - put titles into Google, and you will see the sources - if you have any problems, let me know:

Lee YH, Cheng CK, Tsuang YH.
Biomechanical analysis in ladder climbing: the effect of slant angle and climbing speed.
Proc Natl Sci Counc Repub China B. 1994 Oct;18(4):170-8.


SLIP & FALL MECHANICS - has a good analysis of the risks/problems involved in ladder climbing:
By Dennis R. Andrews, Ph.D, PSP, CECD
http://region1.asse.org/docs/CoPs_article_0703.doc

Biomechanics During Ladder and Stair Climbing and Walking on Ramps and Other Irregular Surfaces, by A.S. Merryweather and D.S. Bloswick
IN: Biomechanics in Ergonomics, Second Edition
Shrawan Kumar - borrow from library, or buy e.g. from Amazon

An ergonomic analysis of the ladder climbing activity
Authors: Bloswick, Donald S. & Chaffin, Don B.
IN: ." International Journal of Industrial Ergonomics 6(1): 17-27. Jul-1990
Abstract: Injuries from slips, falls and overexertion during ladder climbing activities are common in both occupational and non-occupational environments. Little is known, however, about the task, equipment, and user parameters which may cause these injuries. In order to evaluate the hazards associated with ladder climbing, ten male subjects were tested under combinations of ladder rung separation, ladder slant, climbing speed, and climbing direction. Hand and foot forces, hand torques, torso muscle EMGs and hand and foot locations on the ladder rungs were recorded. A biomechanical model was developed which allowed the evaluation of dynamic joint moments and back forces. Study results include safety and biomechanical design guidelines relating to the effect of the task, equipment, and user parameters on climbing safety. Under the conditions studied there does not appear to be a significant slip hazard for people with reasonable strength and mobility. There may be a potential for climber grip strength to be exceeded under some field conditions and foot slip is possible during the use of vertical ladders. There is also the potential for localized fatigue in muscles acting at the elbow, hip and ankle joints during long climbs. The relatively high measured torso muscle IEMG suggests that certain ladder climbing activities may generate considerable back forces.

Posted By Della Pearlman
I am very conscious of copyright - because these were abstracts of articles, not the articles, they are public access - if you follow the links, you will see there are no copyright restrictions - however if the moderators can show that there are copyright restrictions, I would be pleased to forward the links.

Posted By Della Pearlman
OK here are the references in moderator-friendly form:

Body Movements in Climbing a Ladder
Author: M. E. Dewar http://www.informaworld....ontent=a777786045~db=all

Hip osteoarthritis: influence of work with heavy lifting, climbing stairs or ladders, or combining kneeling/squatting with heavy lifting.
Occupational & Environmental Medicine. 65(1):6-19, January 2008.
Jensen, L K
http://pt.wkhealth.com/p...1tqGTfngf1Jbt7xW3PRytcHn!949623904!181195628!8091!-1

Knee osteoarthritis Influence of work with heavy lifting, kneeling, climbing stairs or ladders, or combining kneeling/squatting with heavy lifting
http://oem.bmj.com/cgi/c...stract/oem.2007.032466v1

Biomechanical analysis in ladder climbing: the effect of slant angle and climbing speed.Lee YH, Cheng CK, Tsuang YH.
http://www.ncbi.nlm.nih....ortPanel.Pubmed_RVDocSum

SLIP & FALL MECHANICS
By Dennis R. Andrews, Ph.D, PSP, CECD
http://region1.asse.org/docs/CoPs_article_0703.doc

Biomechanics During Ladder and Stair Climbing and Walking on Ramps and Other Irregular Surfaces, A.S. Merryweather and D.S. Bloswick
IN: Biomechanics in Ergonomics, Second Edition
Shrawan Kumar
(read online at: http://books.google.co.u...esult&resnum=2&ct=result )

An ergonomic analysis of the ladder climbing activity
Donald S. Bloswick & Don B. Chaffin
http://www.sciencedirect...1c2690cd8d27d2e2675fcac6