BS 466:1984 download.British Standard Specification for Power driven overhead travelling cranes, semi-goliath and goliath cranes for general use .
1. Scope
BS 466 specifies requirements for powerdriven overhead travelling cranes, semigoiiath and goliath cranes for general use.
NOTE 1. Typical crane types i shoi w t.gure 1.
The clauses of BS 466 that deal specifically with the means of power do not apply to d.c., hydraulic or pneumatic powered cranes, but the remainder a’ the standard can be applied to the design and construction of cranes of these types where relevant.
BS 466 does not apply to fixed runways (usually single track) of the type dealt with in BS 2853 or jib cranes.
NOTE 2. The titles of ti’,s pubUcatlons Nte.d to In this standard are listed on the Inside back cor.
2. Definitions
For the purposes of BS 466, the following definitions apply.
2.1 crab (or trolley). An assembly incorporating one or more lifting units that traverses the bridge of the crane.
2.2 duty cycle. A cycle of electrical input(s) to a motor(s) that commences when a lod is picked up and ends when the crane picks up the next load.
2.3 gollath crane. A crane comprising a bridge supported by legs and capable of travelling on tracks at ground or deck level.
2.4 semigoliath crane. A crane comprising a bridge supported at one end by leg(s) and at the other end by an end carriage(s) capable of travelling along tracks, one at ground or deck level and the other elevated.
2.5 Operational characteristcs of control
2.5.1 complet. start. Operation of the controller by holding the control in a fixed position until nominal rated speed is reached.
2.5.2 jogging operation. Operation of the controller to give partial starts.
2.5.3 electalcal braking. Motor torie applied In the direction opposite to the existing motion (i.e. as a braking torque).
2.6 overhead travelling crane. A crane comprising a bridge supported by end carriages capable of travelling along elevated tracks.
2.7 sat. working load of a crane. The maximum load that, under specified conditions, is permitted to be safely handled by the crane.
3.2 Information to be provided by the manufacturer. The manufacturer shall provide information to the purchaser of the crane being offered In accordance with appendtx C.
4. Claulfication
The classification of the crane as a whole and of each mediaiun shall be based on the Information provided in accordance with appendix A and shall be determined in accordance with appendix 0.
5. Service conditions
5.1 Normal servic, conditions. For normal service
conditions, the crane shall be pplied for:
(a) indoor use
.
(b) use at ambient temperature between -10 C and 40°C with no sources of high local heating, such as furnaces or radiant panel heaters;
(c) use at an altitude not exceeding 1000 m above sea level;
(d) use in clean still air of normal humidity and free from contamination and deposits.
5.2 Special service conditions
5.2.1 General. The manufacturer shall take any special service conditions required by the purchaser into account and agree with the purchaser how he proposes to meet each of these requirements and any limitations imposed In consequence of the special conditions.
NOTE. Attention Is dra’vmi to appendix A which gives examples of medal airvics conditions tIat may require special attention.
5.2.2 Additional requirements
5.2.2.1 Hand!ing molter, metal. For cranes ud for handling molten metal, the minimum classification for the lifting unit mechanism relative to the hazardous load shall be M5 (see table 13) and the lifting rope shall have a metal core.
If the crane has excess capacity to a lower classification for other use, then the crane markings (see 45.1) shall specify the maximum permissible weight of the hazardous load, i.e. Maximum full ladle weight . tonnes.
5.2.22 Potentially explosive atmosphere. Cranes for potentially explosive and flammable atmospheres shall be designed to meet th. appropriate ignition protection requirements corresponding to the environmental conditions under which they will be required to work asspecifiedin 8S5345.
5.2.2.3 Outdoor u
522.3.1 Weather protection. Th. manufacturer shall arrange weather protection for all electrical and mechanical equipment, as necessary, to meet th. condItions specified.
The weatherproof ing shall make allowances for the temperature rise of equipment under normal operating conditions,
(d) Power released brakes shall be applied automatically b spring(s) or wei1t(s) when the power supply to the brake is interrupted. Power applied brakes shall not be fitted without a back-up sy tern of the power released type.
(e) Brakes shall be provided with means of adjustjr.ent to compensate for wear.
(f) Springs for electromechanical brakes shall be of the compression type and shall not be stressed in exces of 80 % of the elastic limit of the material.
(g) Under service conditions brakes applied by hand shall not require a force greater than 710 N (25 lbt) at the handle. Brakes applied by foot shall not require a force of more than 180 N (40 lbf) on the pedal.
(h) Brakes shall be protected from hostile environments likely to adversely affect their operation, including rain, oil and grease.
20.2 Hoist brake. A hoist brake shall be provided which. when the power is cut oft or fails, will arrest the motion and hold at rest any load up to and including the overload test load (s.e clause 44) at any position of th. lift. Th. load shall be brought to rest in the shortest time consistent with safe crane operation.
Provision shall be made to enable any load capable of overcoming the friction in the system up to and Including th. overload test load to be lowered safely in a controlled manner in the event of power failure.
The brake shall be designed to exert a restraining torque of at least 50 % greater than the maximum torque transmitted to the brake drum from the suspended load under service conditions. In estimating this torque, the effects of friction in the transmission system between the load and the brake shall be ignored.
20.3 Long travel motion brakes. Cranes shall be fitted with a long travel motion brake(s) capable of bringing a fully loaded crane to rest, without shock, from the highest speed it can attain (see also 5.2.2.3.4).
When a foot operated brake Is provided in a cabin mounted on the crane bridge, the brake pedal shall be designed and positioned to facilitate safe operation of the crane by the driver.
Whan a crane Is controlled from other than a cabin mounted on the crane bridge, the long travel motion brake(s) shall be of the refused’ type.
20.4 Cross traverse motion brakes. The cross traverse motion of a crane shall be provided with a brake(s) if:
(a) the specified traversing speed under full load is
greater than 32 rn/mm;
(b) th. crab is mounted on anti fnction bearings;
(c) the driver’s cabin Is attached to the crab:
(d) th. crane is for outdoor use (see 5.22.3.4). The cross traverse motion brake(s) shall be capable of bringing the fully loaded crab to rest, without shock. from the highest speed it can attain.