BS 7212:1989 pdf free download.Code of practice for Safe use of construction hoists.
1 Scope
BS 7212 code of practice gives guidance for the safe use of all types of hoist defined in Regulation 4 of the Construction (Lifting operations) Regulations, 1961 as a lifting machine, whether worked by mechanical power or not, with a carriage, platform or cage the movement of which is restricted by a guide or guides”. Such hoists are designed. constructed and used as temporary installations during construction work. The guidance covers various types of “goods only” hoists as well as hoists for both passengers and materials. The aspects dealt with include safe systems of work, management, planning general recommendations for the selection, installation, testing, examination, operation and maintenance of construction hoists as well as guidance for the selection and duties of erectors and operators.
The legal responsibilities for the safety of persons working on construction hoists, which may be shared by employers of those persons working on construction hoists, by persons working on construction hoists and by persons having effective control of the construction site are summarized in Appendix A together with examples of UK legislation and related documents which may also be applicable to construction hoists, depending upon their location.
A schedule of statutory requirements relating to the use of construction hoists is given in Appendix B.
NOTE The titles of the publications referred tom this standard are listed on the inside back cover.
2 Definitions
For the purposes of BS 7212 the following definitions apply.
2.1
appointed person
the person. appointed by the management or organization requiring the hoisting operation to be undertaken, who will be responsible for all aspects of the hoisting operations
2.2
competent person
a person who is deemed to be competent and has such practical and theoretical knowledge and such experience of the construction hoist and its equipment as is necessary to carry out the function to which the term relates in each particular context
4.1.3 Rack and pinion goods hoists [see Figure 1(c)]. Rack and pinion goods hoists have a platform which is usually fitted with side panels to retain the load on the platform. Where these side panels are not fitted, an enclosure should be provided for the full height of travel. Persons are permitted to walk onto the stationary platform for purposes of loading and unloading only, but are not allowed to travel on the platform, except for the occasions of erecting, maintaining, inspecting and dismantling the hoist at which time the machine is functioning as a work platform and should be controlled solely from the platform.
When in service, it should be possible for the hoist to be operated from only one position at any one time. This control position is normally at base level or any other position or level which affords good visibility over the entire range of level of travel. They should not be operated from the platform when in service. Gates are required at each landing: it is desirable that these, as well as gates fitted to the platform, are provided with effective interlocks, especially at the ground level.
4.2 Rope driven hoists
4.2.1 General. Rope driven hoists consist of a
platform (or cage) raised and lowered by means of a steel wire rope (or ropes).
The following two methods of drive are commonly used:
a) by traction drive using sheave(s) and steel wire rope(s) with a counterweight;
h) by wire rope winding drum, without a counterweight.
The drive for a goods only hoist may be derived from any type of prime mover, but in the case of
passenger hoists the drive is invariably electric in order to facilitate the operation of all interlocking safety devices.
The platform (or cage) is continuously guided and the guides can be either part of a mast structure or part of an enveloping tower.
Whether the guides are part of a mast structure or an enveloping tower the hoist can he freestanding only up to a limited height, above which ties are
required at regular intervals to support it from a building or structure.
Where the guides are part of an enveloping tower, the tower can be freestanding to a height which can be greater than with a mast alone, especially if the tower is formed from structural steel sections.
Where the tower is formed from scaffold
components, it is usually tied into the main scaffolding around the building.
10.5.5 Certain types of goods hoist are provided with safety gear which is actuated when a loss of tension in the suspension ropes occurs.
One method of checking the efficiency of such arrester gear is to raise the loaded platform about one metre and support it with a prop which can be readily pulled or knocked out when the suspension ropes are allowed to become slack. A pole or rope should be used to remove the prop so that the person carrying out the test can remain at a safe distance from the platform. The safety gear should stop the loaded platform in a distance not exceeding 75 mm. Alternative methods have been used to good effect.
10.6 Tests following alterations in the height of travel or since the hoist was last erected
10.6.1 In the case of a passenger hoist, it is a statutory requirement that, after an alteration in the height of travel or since it was last erected, it shall be tested and thoroughly examined. During this test the rated load should be carried throughout the full height of travel.
Although it is not a statutory requirement to carry out any similar tests when goods hoists are extended or re-erected it is considered good practice to do so.
Before any load tests are carried out, a thorough check should be made of all new connections between mast or tower sections, together with ties and their points of fixing to the mast or tower and adjacent structures, to establish their integrity. The correct positioning and functioning of top limit switch ramps should be checked together with the correct operation of any new landing gates by driving the cage or platform without a load upto the new top operational level.
10.6.2 The statutory requirement for a passenger hoist and the considered good practice for a goods hoist to be subjected to functional overspeed testing of the safety gear after an alteration in height, may coincide with the statutory, need for safety gear checks at periods not exceeding three months as required by the Certificate of Exemption for rack and pinion hoists. When deciding how extensive the test and examination of a safety device should be when it does not coincide with the requirements of the Certificate of Exemption it is reasonable to take account of any previous tests and examinations made either after initial erection or previous extension which confirm that the hoist is basically satisfactory.