Reducing Sprains and Strains in Construction
Through Worker Participation -- A Manual for Managers and Workers
with Examples from Scaffold Erection |
|
Ernst A.P. Koningsveld, Peter
Vink, Ilse J.M. Urlings, Annelise M. de Jong
NIA TNO, Amsterdam, The Netherlands
CPWR – Center for Construction Research and Training
This manual is based on a report produced in Dutch and funded by Arbouw,
the Netherlands: Urlings, I.J.M., P. Vink, and H.F. van der Molen, Handleiding
om de lichamelÿke belasting van steigerbouwers te verminderen (How to reduce
the physical workload of scaffold erectors). Amsterdam: Arbouw, 1994.
Summary
Background
How to Develop a Company Program to Reduce Sprains and
Strains
- Organize the program
Scaffold erection hazards
- Tell everyone about the program and have workers list the hazards
Scaffold erection: Solutions in the pilot projects
- Get ideas and choose some solutions
Scaffold erection: Solutions in the pilot projects
- Test some solutions
Scaffold erection: Evaluation of the worker-participation process
- Implement the best solutions
- Evaluate the results
Scaffold erection: Evaluation of the process
Related Research Documents
Appendixes
A. Questionnaire and Hazards Inventory
B. Dutch Guidelines for Manual Handling of Materials by
Scaffold Erectors
C. Potential Solutions
D. Shortcomings, Bottlenecks, and Potential Solutions
E. Measurements to Verify the Hazards and the Solutions
F. Results of the Scaffold Erection Tryout in the Netherlands
Scaffold erection work is physically demanding. It requires manual handling,
lifting, and carrying of heavy materials and work in awkward postures. As
a result, scaffold erectors suffer from a relatively high rate of work-related
injuries, most of them musculoskeletal.
This manual presents ways to make the work safer, based largely on ideas
from workers. When workers help develop a manual, the proposed solutions
are practicable and relatively easy to implement. In addition, this active
involvement of workers -- "participatory ergonomics" -- tends to result
in more-motivated workers, less absenteeism, higher-quality work, and
better productivity.
Using the methods described here, pilot projects were conducted in two
scaffolding firms in the Netherlands, one small (15 scaffold erectors)
and one medium size (50 erectors).
The two companies each completed six steps:
- Organize the program
- Have workers list sprain-and-strain hazards
- Get ideas and choose some solutions
- Test some solutions
- Implement the best solutions
- Evaluate the program.
The main hazards turned out to be related to lifting, lowering, and
otherwise moving materials. For all hazards, potential solutions were
generated in special brainstorming sessions. All of the participating
scaffold erectors graded the potential solutions 1 to 10, with 1 being
"unrealistic" or "impossible" and 10 meaning "excellent
and easy to do".
Proposed solutions were implemented in a trial. The evaluation found
that several solutions are easy to implement and help reduce the physical
workload. The most feasible solutions included a plank dolly (pallet truck),
an electrical winch, shorter ladders and boards, and shoulder protectors.
In particular, shoulder complaints were reduced. Almost all of the participating
scaffold erectors said they preferred to work with the developed solutions.
Management at both firms found the participatory ergonomics a positive
experience and said this approach can be applied easily in other companies.
Although specific examples relate to scaffolding, this method can be
applied to other work tasks or situations.
Scaffold erection work is physically demanding. It requires manual handling,
lifting, and carrying of heavy materials and work in awkward postures. As
a result, scaffold erectors suffer from more health complaints than most
other tradesmen. (This is documented in the research literature.) More than
half of the serious health complaints are related to musculoskeletal injuries,
compared with one in three for construction overall.
In 1990, Arbouw distributed a questionnaire among scaffold erectors
in the Netherlands. (Arbouw is the Dutch construction industry's program
for safety and health research and promotion.) The results -- based on
responses by 100 of those polled -- show that almost all scaffold erectors
work with heavy loads. The exact question was, "Do you often work manually
with (too-) heavy loads?" More than 80% of the respondents reported that
serious physical strain is a common aspect of their work. For 88%, manual
handling is the usual way of transporting and lifting materials.
Given these problems, the researchers sought to develop solutions that
would meet the needs of scaffold erectors and be easy to implement. The
approach used, known as participatory ergonomics, enlists workers to improve
work practices to reduce sprains and strains. Workers are well aware of
the shortcomings, bottlenecks, and other problems in their work. The use
of their insights can produce effective solutions that workers readily
adopt.
Management at two scaffolding firms used participatory ergonomics to
reduce the physical workload of the workers. A staff safety expert and
workers used a step-by-step approach to develop solutions for hazardous
aspects of the work.
This manual describes how to use participatory ergonomics and presents
such solutions for scaffolding. Action boxes throughout the text specify
agendas for meetings to move the program forward. Sample questionnaires
and other documents are in appendixes A through E. The approach is one
that can be applied to many other aspects of construction work.
Thus, the manual is set up to accommodate two different approaches.
Odd-numbered pages -- page 1, 3, 5, and so on -- have general information
about organizing a company program to reduce sprains and strains. Even-numbered
pages (on the left side) provide some details about the scaffolding program,
such as scaffolding hazards and scaffold-specific solutions. Please note:
The even-numbered pages should not be given to scaffold-erection workers
during a worker-participation program. Having such detailed information
in advance might discourage creative suggestions.
Any company can use this manual to develop and implement its own improvements.
Success depends on having workers and management closely follow the steps
outlined here. The outcome should be improved safety and productivity.
It is not easy to implement new work practices. A key reason is that it
is normal to resist change, even if the outcome is likely to be an improvement.
Because workers are familiar with an old set of procedures, it can take
time to implement new methods, tools, or materials. During such a transition,
management and supervisors must demonstrate tact and flexibility. In addition,
worker participation in the process is essential.
Worker participation is more than a brief discussion or the transfer
of information. A step-by-step approach is best, with a mix of large-group
and tool box meetings.
These are the steps to follow:
- Organize the program
- Have workers list the hazards
- Get ideas and choose some solutions
- Test some solutions
- Implement the best solutions
- Evaluate the results.
Step 1. Organize the program
To begin the process, participants should indicate their support for it.
Top management, middle management, and worker representatives should meet
formally and agree unanimously to work toward a successful project. The
group should set up a steering committee and define its responsibilities.
The company owner should appoint a program manager to manage the process.
Management should make clear at the outset that every suggestion is worth
considering — none should be ruled out immediately and no worker will be
fired or otherwise punished for expressing an opinion on the committee.
Members of the steering committee should include:
- One or two workers (depending on company size)
- A general foreman (a team leader on the job)
- A project manager (usually a supervisor of a large site or more than
one site)
- The general manager.
Workers on the committee should include one member of each trade in
the company that does the work. For instance, if carpenters and painters
finish drywall, both should participate in a steering committee on drywall
finishing.
A technical expert — an ergonomist or industrial hygienist — should
attend every meeting and be available for consultation throughout the
process. The expert should be able to assess the effect of all proposed
solutions on worker sprains and strains.
Small firms may want to work on this program with one or two other small
companies to cut program costs for the tryouts and the technical expert.
And having a larger pool of people may help produce more good ideas.
1st meeting of the steering committee
- Introduce all committee members and the program goals.
- Explain the step-by-step approach.
- Agree on how the results of committee meetings will be reported
- Plan for step 2.
- Prepare for toolbox talks or other ways to tell all workers
about the program. Assign responsibilities for preparing toolbox
talks or printed handouts.
- Arrange supplies (pencils, paper) for workers to list all
the hazards.
- Set a time for the next steering committee meeting.
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Two companies in the Netherlands tried the participatory ergonomics
approach. This section provides suggestions based on those companies'
experience. (It is best to keep this list only for reference by the steering
committee. If people in toolbox meetings are not given suggestions in
advance, they may think of more ideas. And, people tend to be more enthusiastic
about their "own" ideas and solutions.)
The scaffold erectors listed the following hazards on their questionnaires.
- Moving and storing materials - Supplying them and moving them on
the ground. Materials are often stored on site in the wrong order and
too far from scaffolding. Moving the materials to the scaffold adds
unnecessary physical strain. The ground is not always level enough to
move materials by cart.
- Lifting and lowering of materials - Scaffold erectors say the manual
vertical transport of materials along the scaffold is the part of the
job that causes the most strain.
- Heavy materials - Examples are ladders, boards, and pipes longer
than 13 feet. (The workers divided materials into two categories, regular
and heavy. The workers considered the handling of heavy materials as
a separate hazard.)
- Cooperation on teams - Failures to communicate or cooperate can lead
to delivering the wrong parts to the scaffold erectors.
- Other hazards - These include pressure on the shoulders when carrying
loads or mounting parts above head level. Scaffold erectors say the
cleaning of scaffold parts when dismantling is a strain.
Compared with a group of 7,000 workers in all occupations in the Netherlands
who also reported their health complaints for the preceding year, the
scaffold erectors reported a higher rate of shoulder problems
(fig. F-1). In the Netherlands, no other musculoskeletal complaints
from the scaffold erectors were significantly higher than among other
workers.
Step 2. Tell everyone about the program and have workers list the hazards
The first toolbox talk(s) for the program should describe the step-by-step
approach to everyone who might be involved. The program manager should meet
with workers and foremen in small groups to encourage discussion, with no
more than 15 people at a time. Talk about the program goals and the step-by-step
approach.
Invite everyone to fill in the questionnaire about sprain-and-strain
hazards on the job (appendix A). The questionnaire
should be filled out at the meeting. Call a 10-to-15-minute break; this
gives the technical expert time to review the completed questionnaires.
After the break, ask the technical expert to present the questionnaire
results. The group should then discuss the hazards to make sure everyone
understands them.
On the same day or within a few days, the program manager should meet
and discuss the program with everyone else who will work on it -- for
instance, planners, storage personnel, and equipment movers. (These meetings
do not need to be formal meetings.)
1st toolbox meeting(s) for workers and foremen
- Explain the program.
- Tell who is on the steering committee and what it will do.
- Everyone fills out the questionnaire and lists sprain-and-strain
hazards.
- Have the group decide how they will be informed about the project
while it is under way -- e-mail; someone to telephone them, as
needed; or a weekly memo, for instance.
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After each meeting, the technical expert should focus on bottlenecks
in categories like these:
- The supply of materials and their transport on ground level
- Lifting and lowering materials
- Materials -- their weight and usability
- Other physical effects (such as, pressure on the shoulders from heavy
loads)
- Cooperation within teams
- Other aspects.
Scaffold erection: Solutions in the pilot projects
- Placement of materials close to the spot where the scaffold is to
be built and in the right order.(Sometimes materials needed first were
at the bottom of the dolly).
- Development of a plank dolly. Important specifications were:
- Large wheels for transport over uneven surfaces
- They should be arranged like a plank dolly
- Their dimensions should be small enough to pass through gates
and doors.
- Ladders no more than 10 feet long. Longer ladders are difficult to
handle.
- Electrical winches for lifting and lowering.
- Boards no longer than 13 feet. Longer boards are too heavy -- more
than 60 pounds -- especially when wet (see Dutch guidelines for manual
handling, appendix B).
- A work plan, including plans for unloading. Movement of materials
can be reduced if materials are put together that need to be used together.
- Shoulder pads in workclothes. Although carrying should be eliminated
as much as possible, workers will still need to carry some materials
on their shoulders. The pads should cover a large area and be waterproof.
- A scaffold that must be dismantled should be cleaned first by the
contractor who used it. This point can be included in a contract.
The first five solutions were tested in pilot projects. The last three
solutions were tried without testing; the steering committees were confident
that they would work.
Later, a model for a lightweight platform was developed (but it is not
yet available for sale). It is made of a fiber-reinforced synthetic material
and less than half the weight of the traditional wooden one. The new platform
is more expensive, but the Netherlands researchers believe the extra costs
will be compensated for by higher productivity and less absenteeism.
Scaffold erectors and foremen gave most of the changes high scores,
indicating acceptance
Average ratings of changes by 60 scaffold erectors and foremen, two firms,
the Netherlands, 1994
Step 3. Get ideas and choose some solutions
2nd meeting of the steering committee
- Go over the list of hazards from questionnaires
(appendix C).
- Choose hazards for further consideration.
- Set criteria the solutions should meet.
- Set a time for the next committee meeting.
- Set toolbox meetings with workers and foremen.
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The steering committee will go over questionnaires that were filled
out in toolbox meetings and will make a list of hazards for further consideration.
The committee will also set criteria for solutions -- such as payback
time or the maximum amount to be invested.
Toolbox meetings are essential to the program.
The best solutions for major problems usually come from toolbox meetings.
At each meeting, to get ideas, put up a sign, a slide, or a video showing
each hazard. One hazard might be carrying parts on a shoulder. Ask each
person to write down ideas for improvements on his or her own paper. You
may also want to add some solutions; suggestions for scaffolding are listed
in appendix C.
Then, one at a time, ask people to give their ideas and discuss their
pros and cons with the group.
Toolbox session(s) to think up solutions - no more than
15 people per meeting
- Tell what the session is for.
- Explain the hazards that are listed.
- For each hazard, each person lists ideas for solutions.
- Discuss likely effects -- good and bad -- of each proposed solution:
- Equipment that is needed and whether it is available
- The likely effect of the change on how the work is done
- Likely costs
- Likely benefits, including effects on sprains and strains
(with input from the technical expert).
- A list of all potential solutions and their likely effects should
go to the steering committee.
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After each toolbox session, you should have a list of all potential
solutions and their likely effects. From these lists, the steering committee
will select the solutions that appear to be realistic.
3rd meeting of the steering committee
- Review lists of proposed solutions and likely effects (from
toolbox meetings).
(The committee may want to refer to appendix D.)
- Check: Do the proposed solutions meet the criteria that were
set earlier?
- Select (feasible) solutions to be presented to all workers.
- Plan a meeting to present the potential solutions to all workers.
- Set a time for the next committee meeting.
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The program manager should call a meeting for all the company's scaffold
erectors and foremen and give everyone a copy of the steering committee's
list of possible solutions. Each solution is described; a drawing is added
where needed. Each scaffold erector or foreman should grade each solution
on the list from 1 to 10. A "1" is given to unrealistic or impossible
solutions. A "10" means excellent, easy to do. Copies of the lists are
all turned in to the program manager.
After counting the average rating of each solution, the preferences
of the scaffold erectors should be clear. If the overall opinion of a
proposal is not clear, everyone should discuss it to be sure there is
no misunderstanding.
The committee should discuss the narrowed-down solutions with planners,
storage personnel, and equipment movers. Their involvement at this point
is needed to gain their support.
Step 4. Test some solutions
The steering committee has to choose which solutions to try. To avoid expensive
mistakes, it is a good idea to test potential solutions on a small scale.
It is easier to make adjustments in a trial situation. Again, all who will
be involved with the improvements should be told about the trial.
4th meeting of the steering committee
- Go over worker ratings of the proposed solutions.
- Choose solutions to try out.
- Discuss likely consequences of the proposed solutions.
- Assign workers to trial teams. (This may be the company's decision
or be left to volunteers.)
- Plan the trial projects.
- Decide who will evaluate the trial(s) and how.
- Set a time for the next steering committee meeting.
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The program manager should meet with the workers assigned to each trial.
Explain clearly the purpose and procedures of the trial. Then start the
trials for several weeks. The first days are key to success of the trials.
Managers and foremen should watch out for any problems that arise to solve
them quickly and adequately.
The technical expert can verify the effects of the improvements and
possibly estimate costs and benefits -- equipment needed, worker time
saved, injuries prevented, and so on. The steering committee can consider
the trial results in its next (5th) meeting, about three weeks after the
trials end.
5th meeting of the steering committee
- Hear and discuss reports of the trial teams.
- Decide which solutions to implement.
- Plan a session with all workers.
- Set a time for the next committee meeting.
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Session with all workers
- The steering committee head reports on experiences of the trial
teams.
- Explain the solutions to be implemented and likely effects
-- good and bad -- for workers.
- Explain any goals you are setting. (If a solution for a problem
is not immediately obvious, one goal would be to develop a solution.)
- After the whole group discusses the solutions and goals, ask
if the group agrees to the changes.
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Scaffold erection: Evaluation of the worker-participation
process
To evaluate the process, the researchers interviewed program managers
in the two pilot firms. In addition, workers were asked to fill in a brief
questionnaire. The response rate on the questionnaires were 87% (13 of
15 scaffold erectors) in the smallest firm and 26% in the other. The rate
may have been low in the larger firm because the workers are not accustomed
to paperwork and management did not push for help on this.
The participatory process
All respondents consider the projects valuable, and more than 60% of them
indicate that the information provided and participation were sufficient.
The pilot firms stated that the step-by-step approach was part of the
success. The medium-size firm wrote:
- The project, Reduction of Physical Strain of Scaffold Erectors, was
a positive experience for us. Initial skepticism among scaffold erectors
changed into full commitment and participation. Their involvement in
the generation of solutions and in the pilots made the project attractive.
When implementing the solutions other advantages of the participatory
approach became clear. The fact that workers had generated the solutions
themselves, made it more easy to get support in practice. The procedure
was clear; the frequent feedback to all kept the process vivid. The
support of the ergonomists was not only useful, but in our opinion a
necessity for a successful project.
Implementation of improvements
The small firm wrote:
- Some solutions could be implemented immediately:
- a drawing of the layout of materials for each project
- the planning and ordering of the supplied materials and parts
from the storehouse to site in the order in which they will be used
- frequent instruction in good working methods
- the supply of shoulder protection.
- Further attention will be given to the other recommendations.
- The development of lightweight boards scaffold board is under way
We expect that these can be introduced in 1994.
The project managers of both pilot projects reported that the nine improvements
with the highest ratings had been implemented (four had not). Worker participation
was an important factor for successful implementation and continuation,
according to the managers.
The responding workers reported that all of the selected improvements
were implemented, but not on all sites. The workers indicated most improvements
were positive. The plank dolly, especially, is a great success. The shorter
and lighter-weight ladders and boards reduce physical strain and are easier
to handle. Only two of the responding scaffold erectors have used an electric
winch, but they are very positive about the effects on the workload. The
shoulder protectors and the training in lifting and carrying reduce stress
from the work but not the workload.
Step 5. Implement the best solutions
At this point, it is management's responsibility to:
- Plan implementation of (at least) the best solutions
- Buy or produce needed equipment
- Train workers and supervisors
- See that solutions are made part of daily practice
- Monitor the results.
Step 6. Evaluate the results
After the company has tried the new solutions for several weeks, interview
some workers (separately or in small groups). You could ask all or a few
of the workers to do this, depending on how big the company is.
Ask in detail about their experiences using the new methods: What do
the workers think of the changes and do they have suggestions for further
improvement? Give the workers time to answer fully.
In a big company, use the questionnaire to guide the discussion; the
questionnaire helps you learn whether the solutions are still being used.
In a small company -- where you may already know if the solutions are
being used -- the questions on the questionnaire can still help to bring
out any small problems and keep the workers involved.
If a solution isn't being used regularly, it is important to know why.
Once you know why, you can change the proposed solution and try it again.
6th meeting of the steering committee
- Report of all implemented solutions and the evaluation of them.
(The committee may want to look at appendixes
E and F.)
- The committee should cover:
- The participatory process
- Implementation of changes
- Whether safety and health has improved
- Effects on costs and productivity.
- Discuss any potential changes to the solutions that were tried.
- Consider a follow-up evaluation in 12 to 18 months.
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Scaffold erection: Evaluation of the process
Improved health and safety
Any change in the rates of absenteeism and injuries could not be assessed,
because of the small number of workers involved.
The two firms were, however, positive about the effects on the workload.
Their reactions can be summarized:
- The reduction of physical strain had a positive effect on the working
conditions. Some hesitations in the start were the result of "getting
accustomed to a new approach." The new approach, the involvement of
scaffold erectors in the whole process, made workers consider their
work differently. This consideration resulted in several valuable and
some less useful solutions. Other solutions can be tried in the future.
Costs and savings
The medium-size company wrote:
- In many cases practical and financial criteria are very predominant
for companies. This project helped us learn that "faraway" solutions
can be used and are advantageous for both workers and the company.
Because the management and workers had generated, implemented, and evaluated
the solutions, the technical and organizational feasibility was agreed
upon. The costs of improvements could be incorporated in the regular budget
for investments. The direct costs were a loss of work hours for reorganization
and tests. At each firm, three scaffold erectors were busy with the tests
for two days (paid by the company, not a client). So those six workers
were not available for paid work. All other sessions with scaffold erectors
were held in routine company meetings. The steering committee meetings
did cost several hours of pay for workers.
Productivity
Productivity gains were considered likely, but were not assessed. In several
cases, two scaffold erectors can form a team where three workers were
previously needed. In both firms, the projects were considered successful
companywide and management does not intend to study productivity further.
Urlings, Ilse J.M. 1994. Oplossingen bedenken samen met het bedrijf (Generating
solutions in collaboration with workers and management). In: Peter Vink
and Jan Dul, eds. , Lichamelijke belasting tijdens arbeid: wetgeving
en oplossingen (Physical loads at work: legislation and solutions).
The Netherlands: Kerckebosch, Zeist, 77-82.
Vink, Peter, Ilse J.M. Urlings, and Edith Wortel. 1994. Succesvol
invoeren van verbeteringen met 'participatieve ergonomie' (Participatory
ergonomics: a way to implement successfully). In: Vink P, Dul J, ed. Lichamelijke
belasting tijdens arbeid: wetgeving en oplossingen (Physical loads
at work: legislation and solutions). The Netherlands: Kerckebosch, Zeist,
69-76.
Please answer the questions below about working conditions found on most
sites.
Shortcomings and bottlenecks |
Does the ground need to be leveled before the scaffold
is erected? |
___ no ___ yes. |
If yes, are needed tools available? |
___ no ___ yes. |
Are needed materials and parts close to where the scaffold
is to be built? |
___ no ___ yes |
Do workers have to carry parts more than 30 feet? |
___ no ___ yes |
If yes, is there equipment to transport the materials?
|
___ no ___ yes |
Do you often carry materials and parts on your shoulders?
|
___ no ___ yes |
Are the correct parts and materials ordered and delivered
for building the scaffold? |
___ no ___ yes |
|
Do you build scaffolds higher than 40 feet? |
___ no ___ yes |
If yes, Do you use equipment to lift and lower parts
and materials? |
___ no ___ yes |
Do you often build small scaffolds? |
___ no ___ yes |
Do you build according to a drawing? |
___ no ___ yes |
Do you handle ladders 13 feet long or longer? |
___ no ___ yes |
Do you handle boards of 1.5 inches that are more than
13 feet long? |
___ no ___ yes |
Do you handle poles 16 feet or longer? |
___ no ___ yes |
|
Do you handle platforms? |
___ no ___ yes |
Are these used when the height between two levels is
more than 6.5 feet? |
___ no ___ yes |
Do you often anchor scaffolds to a building? |
___ no ___ yes |
Do you drill when anchoring a scaffold? |
___ no ___ yes |
Do you have enough support for your feet and body when
doing this? |
___ no ___ yes |
Are scaffolds cleaned by others before you dismantle
them? |
___ no ___ yes |
Do you often use equipment that belongs to the site
owner or general contractor? |
___ no ___ yes |
Are there regular meetings for workers to discuss work
issues? |
___ no ___ yes |
Does your company have written procedures for building
a scaffold? |
___ no ___ yes |
Have you been trained in how to lift and carry? |
___ no ___ yes |
Is there enough personal protective equipment for your
work — ear plugs, hard hats, fall protection, and so on? |
___ no ___ yes |
Appendix B: Dutch Guidelines for Manual Handling of
Materials by Scaffold Erectors
Arbouw is a nationwide labor-management organization in the Netherlands
for the improvement of safety and health in the building and construction
industry.
One Arbouw activity is to agree on limits for physical workloads and
to give suggestions for improvement. The limits are based on internationally
acknowledged scientific research.
The maximum allowable weight is considered safe for 25% of the male
population to lift. In practice, workloads still exceed the weight limit,
so the limit indicates values that should be met.
As soon as technical or organization developments make a lower weight-limit
feasible, the limit will be reduced.
These are the workload weight limits for individual scaffold erectors:
Material |
Workload weight limit for scaffold erectors (Considered
safe for 25% of the male population) |
Interim workload limit for scaffold erectors (Based on
economic feasibility) |
Scaffold poles, boards, platforms |
33 pounds (15 kg.) |
51 pounds (23 kg.)
|
|
- See A-blad steigerelementen (Arbouw guidelines for scaffold
materials). Amsterdam: Arbouw, 1997.
Appendix C: Potential solutions
Solution |
improvement |
available |
impact |
1. Leveling and smoothing |
+ |
+ |
+/- |
HORIZONTAL TRANSPORT |
2. Plank dolly (pallet truck) Can be used in many
but not all situations. Risk of theft. Some extra work.
|
+ |
- |
+ |
3. Trolley with large wheels and long forks, adapted
to the pallets These can transport many materials and a lot of
weight. Careful planning and an even surface are required. Storage
and transport of the trolley can be a problem. |
+ |
+ |
+ |
4. Powered plank dolly (pallet truck) Large wheels
and thick tires are needed for transport over lawns. The truck should
be narrow to go through gates, doors, and hedges. |
+ |
- |
+ |
5. Setting out materials near where they will be
used on site. This helps reduce the need for manual transport.
Collaboration with the owner of the building or installation is required.
|
+ |
- |
+ |
6. Materials that will be used together are kept
together; parts to be used first are on top of piles of materials.
Preparation for the job should take care of this. Storage personnel
must be convinced of the usefulness of this way of organizing materials;
they will have to change the way they do things. |
+ |
+ |
+/- |
7. The loading of containers If a container is
used for transport and no forklift is used, the design of the container
should meet the requirements of easy manual handling. |
+ |
+ |
+ |
8. Hand trucks in several formats |
+ |
+ |
+ |
9. Running board for unloading trucks |
+ |
- |
+ |
10. Unloading materials close to scaffolding site
|
+ |
+ |
- |
11. Using smaller plank dollies (pallets) |
+ |
- |
+/- |
12. Using plank dollies (pallets) with wheels or
rollers |
+ |
+ |
+/- |
13. A planning system for scaffold parts and tools/equipment. |
+ |
+ |
- |
VERTICAL TRANSPORT |
14. Electrical winch Electricity is needed. Protect
the equipment from theft.
|
+ |
+ |
+/- |
15. Rope and wheel (manual winch) Especially useful
for scaffolds more than 26 feet high. One (larger) part after another
can be lifted. A brake is needed. |
+ |
+/- |
+/- |
16. Building the scaffold in modular units, instead
of completing each level before putting any parts on the next level
up Especially for long, straight scaffolds |
+/- |
+ |
+/- |
17. Erection of scaffolds according to a drawing
If you work from a drawing in which all parts can be seen, there
is less chance of making a mistake. |
+/- |
+ |
+/- |
18. Loose pulley with a counterweight |
+ |
- |
+/- |
LIGHTWEIGHT MATERIALS |
19.
Ladders with a maximum length of 10 feet If the company buys only
ladders 10 feet or less, in a couple of years all longer ladders will
have been replaced. All scaffolding needs can be met with ladders
of 7 to 10 feet.
|
+ |
+ |
+/- |
20.
Boards no longer than 13 feet. Buy only boards of 13 feet or less.
Soon the problem of heavy boards will be over. |
+ |
+ |
+/- |
21. Platforms that weigh less than 44 pounds |
+ |
+/- |
+/- |
22. Aluminum parts, where applicable There should
be no problem up to 19 feet high. Risk of theft. |
+ |
+/- |
+/- |
23. Synthetic materials or parts where possible.
|
+ |
- |
+/- |
24. Shorter poles |
+ |
+ |
+/- |
25. Thinner boards |
+ |
+ |
+/- |
ANCHORING A SCAFFOLD TO A BUILDING |
26. Making a wider base to reduce the number of anchors
needed This results in more work to mount the lower part of the
scaffold. More materials will need to be transported. |
+ |
+ |
- |
27. Making an extra horizontal bar at hip height
to lean against A little extra work allows better working postures. |
- |
+ |
+ |
28. First erecting the scaffold and make sure you
have a stable floor before you drill anchor holes This allows
better working postures when drilling. |
+/- |
+ |
+/- |
29. Training erectors (and foremen) on how to anchor
a scaffold |
- |
+ |
+/- |
30. Using a lightweight drill |
+ |
+ |
+ |
31. Using a counterweight to suspend the tool The
balancer should be battery powered or spring loaded. |
+/- |
+ |
+ |
JOB CONTRACT ISSUES |
32. Scaffold must be clean before dismantling Every
worker must keep this agreement, even if this means the scaffold erectors
have to wait. |
+ |
+/- |
+/- |
33. Layout of the workplace Materials shall be stored
close to the scaffold to be built. |
+ |
+ |
+ |
34.
Use of equipment provided by the site owner or general contractor
The use of cranes, ladders, lifts, and so on.
|
+ |
+ |
+ |
COMMUNICATION AMONG SCAFFOLD ERECTORS |
35. Erectors should help prepare a work plan that
has step-by-step procedures for mounting The plan should pay close
attention to safety and health |
+ |
+ |
+ |
36. Job rotation Relieve the worker in the middle,
who has the most straining job. Cooperative deliberation is required.
|
- |
+ |
+ |
37. Training in lifting and carrying All scaffold
erectors should be trained. Training should be both part of apprenticeship
programs and provided on site. |
+/- |
+/- |
- |
38.
Shoulder protection pads These can be sewn inside the overalls. But
scaffold erectors may not wear overalls on warm days. |
+/- |
+/- |
+/- |
39. Backpack frame for carrying parts |
+ |
- |
- |
40. Promote the acceptance of equipment |
- |
+/- |
+ |
41. Improved communication on site |
+ |
+ |
- |
42. Training to select the best materials and parts |
- |
+ |
- |
43. Make parts easily identifiable — with color or
letter codes This is a means to avoid misunderstandings between
scaffold erectors, especially those who are new. It prevents picking
and transport of the wrong parts. |
+/- |
- |
- |
44. Lift with both hands to relieve shoulders when
carrying |
+/- |
- |
|
45. Safety orientation and training on the job |
+ |
+ |
- |
Appendix D: Shortcomings, Bottlenecks, and Potential
Solutions
Below, for each answer to the questionnaire, at least one potential solution
is listed.
Shortcomings and bottlenecks |
Yes or No |
Solutions |
Does the ground need to be leveled before the scaffold is erected?
|
___yes ___no |
1 |
If yes, are needed tools available? |
___yes ___no |
1 |
Are needed materials and parts close to where the scaffold will
be built? |
___yes ___no |
1-13,33-35 |
Do workers have to carry parts more than 30 feet? |
___yes ___no |
1-13, 33-35 |
Is there equipment to transport the materials? |
___yes ___no |
1-13, 33-35 |
Do you often carry materials and parts on your shoulders? |
___yes ___no |
2-13, 19-25, 37, 40, 44 |
Are the correct parts and materials ordered and delivered for building
the scaffold? |
___yes ___no |
5-7,35,43 |
Do you build scaffolds higher than 40 feet? |
___yes ___no |
14, 15, 18-25, 35-37, 40, 45 |
Do you use equipment to lift and lower parts and materials? |
___yes ___no |
14,15, 18-25, 35-37, 40, 45 |
Do you often build small scaffolds? |
___yes ___no |
14-25, 35-37, 40, 45 |
Do you build according to a drawing? |
___yes ___no |
5, 17, 35, 41 |
Do you handle ladders 13 feet or longer? |
___yes ___no |
19, 22, 23, 25 |
Do you handle boards of 1½ inches that are more than 13 feet long?
|
___yes ___no |
20, 33, 23, 25 |
Do you handle poles 16 feet or longer? |
___yes ___no |
22-24 |
Do you handle platforms? |
___yes ___no |
21-25 |
If so, are these used when the height between platform levels is
more than 6.5 feet? |
___yes ___no |
21-25 |
Do you often anchor scaffolds to buildings? |
___yes ___no |
28, 30, 31 |
Do you drill when anchoring a scaffold? |
___yes ___no |
28, 30, 31 |
Do you have enough support for your feet and body when doing this? |
___yes ___no |
26-28 |
Are scaffolds cleaned by others before you dismantle them? |
___yes ___no |
32 |
Do you often use equipment belonging to the site owner or general
contractor? |
___yes ___no |
34 |
Are there regular meetings for workers to discuss work issues? |
___yes ___no |
41 |
Does your company have written procedures for building a scaffold?
|
___yes ___no |
35 |
Have you been trained in how to lift and carry safely? |
___yes ___no |
36, 37, 40, 42, 44, 45 |
Is there enough personal protective equipment for your work — ear
plugs, hard hats, fall protection, and so on? |
___yes ___no |
38, 39 |
Appendix E: Measurements to Verify the Hazards and the
Solutions
To evaluate and verify the results of improvements, measurements can be
made. The technical consultant can conduct the assessments or arrange staff
to do so. Measurements that are briefly described here can be used in step
4, where selected improvements are tried out in trial projects.
Changes in heart rate When someone applies force or moves, the
heart rate will increase. Research has shown that the changes in heart
rate are a reliable measure of physical strain. For detailed studies,
verification of the relation between physical performance and heart rate
of an individual can be made on an ergometer, a laboratory bicycle with
adjustable resistance.
Questionnaires A questionnaire on "local musculoskeletal discomfort"
is useful. Musculoskeletal health problems and discomfort caused by physical
load may have a major effect on employees' productivity and well-being.
For prevention and evaluation of sprains and strains, it is important
to know the size of the musculoskeletal load. Rating discomfort by areas
of the body — shoulder, lower back, and so on — is an easy way to directly
estimate the relative physical load. The questionnaire asks people to
identify the areas where they feel discomfort by using a body map and
then rate the amount of discomfort. (The questionnaire is not included
with this report.)
There is a software program to analyze and present the results of the
questionnaire on local musculoskeletal discomfort. The method is a quick
and easy way to evaluate changes in sprain-and-strain hazards.
Biomechanical studies Biomechanical studies of postures make
it possible to compute loads on joints. In particular, determining the
load on the lower back — the L4/L5 joint — is important for preventing
back injuries. The National Institute for Occupational Safety and Health,
NIOSH, has developed a procedure to assess the biomechanical load of lifting
and carrying and the related force limits.
Productivity Cost-benefit studies that include productivity can
be added to the methods mentioned earlier for evaluating the effects of
improvements — before and after the program. For such studies, use the
calculation methods the company usually uses.
In the Dutch projects the gain in productivity from only one improvement
— setting materials in the right order — was more than 10%, about one
hour a day per scaffold erector.
Appendix F: Results of the Scaffold Erection Tryout
in the Netherlands
For several weeks, two teams of three scaffold erectors each used the new
methods and materials. The changes were compared with traditional work.
(Researchers recorded observations every 30 seconds.)
Figure F-1. Average local discomfort reported by 6
scaffold erectors, using old and new working methods, Netherlands, 1994
0= no discomfort
10= extreme discomfort
Use of the new methods significantly reduced four scaffold erectors'
heart rates on the job (data on two erectors were lost):
Figure F-2. Heart rates of 4 scaffold erectors, using
old and new methods, Netherlands, 1994
The physical workload decreased because the time that scaffold erectors
handled loads of more than 44 pounds was reduced from 25 to 5% of the
total:
Figure F-3. Percentage of time that 6 scaffold
erectors carried more than 44 pounds by hand, Netherlands, 1994
Time-and-motion studies showed that discomfort was reduced on workers'
shoulders and legs, but not on their backs. With the new program, workers
spend less time with their arms lifted more than 60 degrees:
Figure F-4. Percentage of time that 6 scaffold erectors
were observed with an arm elevated more than 60o, using old and new working
methods, Netherlands, 1994
This document appears in the eLCOSH website
with the permission of the author and/or copyright holder and may not
be reproduced without their consent. eLCOSH is an information clearinghouse.
eLCOSH and its sponsors are not responsible for the accuracy of information
provided on this web site, nor for its use or misuse.
This research was made possible by funding of $19,991 from CPWR – Center for Construction Research and Training (CPWR) to Peter Vink, principal investigator.
The funding is part of a CPWR research agreement with the National Institute
for Occupational Safety and Health (NIOSH) under NIOSH grant CCU312014.
The research is solely the responsibility of the authors and does not
necessarily represent the official views of NIOSH. CPWR — the research
and development arm of the Building and Construction Trades Department,
AFL-CIO — is uniquely situated to serve workers, contractors, and the
scientific community. A major CPWR activity is to improve safety and health
in the U.S. construction industry.
© Copyright 1998, CPWR – Center for Construction Research and Training. All rights reserved. Copies of this report may be obtained from
Publications, CPWR – Center for Construction Research and Training, 8484 Georgia Ave, Suite 1000, Silver Spring, MD 20910, www.cpwr.com, tel. 301-578-8500. For
permission to reproduce this document or for bulk copies, contact CPWR.
(Report E1-98)
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