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Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to
information for citizens to secure access to information under the control of public authorities,
in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.

Mazdoor Kisan Shakti Sangathan
"The Right to Information, The Right to Live"

IS 7155-2 (1986) : Code of recommended practice for conveyor
safety, Part 2: General safety requirements [MED 6:
Continuous Bulk Conveying, Elevating, Hoisting Aerial
Ropeways and Related Equipment]

Jawaharlal Nehru
'Step Out From the Old to the New'

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Satyanarayan Gangaram Pitroda
Invent a New India Using Knowledge

Bhartrhari — Nitisatakam
"Knowledge is such a treasure which cannot be stolen"

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PROTECTED BY COPYRIGHT

udc 621-867: 614-8: 006-76 IS : 7155 ( Part 2 ) - 1986

Indian Standard (Reaffirmed 1999)

CODE OF RECOMMENDED PRACTICE FOR
CONVEYOR SAFETY

PART 2 GENERAL SAFETY REQUIREMENTS

( First Revision )

1. Scope — Sets out general safety requirements relating to continuous mechanical handling
equipment, including its construction, installation, utilization and maintenance, to ensure its uses to
the optimum advantage, and to prevent, as far as possible, any accidents or mishaps that could arise
from misuse.

1 .1 These safety requirements shall be in addition to the requirements/information given in
IS : 7155 ( Part 1 )-1986 'Code of recommended practice for conveyor safety: Part 1 General
information'.

2. Application — These safety requirements apply in the normal working conditions defined in 2.3
of IS :7155 (Part 1 )-1986.

2.1 These safety requirements apply to continuous mechanical handling equipment proper, excluding
the structures ( building frameworks, planks, etc ) to which such equipment is affixed or on which it is
placed and for which the user is responsible, except when such structures have been designed, supplied
and erected along with the conveying device.

2.2 The main object of these requirements is the safety of the personnel defined in 2.4 of
IS :7155 (Part 1 J-1986.

2.3 Skilled personnel, such as fitters, maintenance and repair personnel, who only work from time to
time at the request of the person responsible for the plant, shall observe special requirements,
particularly those set out in 3.3.17 to 3.3.21.

2.4 Persons whose duties do not demand their presence on the plant or in the vicinity of the equipment
under consideration shall observe orders forbidding access to certain areas.

3. General Requirements — The construction and operation of all continuous mechanical handling
equipment for loose bulk materials and unit loads shall meet the statutory, specific and other
requirements relating to safety in general; the principles laid down in 1 and the following genera!
requirements.

3.1 In the Construction Stage ( Design and Manufacture )

3.1.1 Design and construction of platform, walkways, stairways and ladders — The design of
platforms, walkways, stairways and ladders shall be such that adequate clearance is provided for
normal operation; servicing and maintenance, giving sufficient room for freedom of movement and
access for carrying out such duties.

3.1.2 Tne stability and strength of the equipment (static or mobile) shall be ensured under alt
normal working conditions, including climatic conditions as agreed to by the interested parties.

3.1.3 The whole conveyor path and especially the loading, unloading and transfer points, shall be
designed so as to avoid as much as possible all spillage of products or conveyed material.

3.1.4 The slopes and the characteristics of the conveying element shall be designed so as to avoid
slipping and/or unintentional dropping of the conveyed products under normal working conditions-

3.1 .4.1 The support element of the material or load ( belt, buckets, swing trays, etc ) shall have
sufficient size to be suitable for the transport of the specified product or load.

3.1.5 To prevent over-running or running backwards of the conveying device, all inclined or vertical
appliances shall include a safety device which operates whenever the motive power is cut off or fails
and where the load conveyed possesses kinetic or potential energy. Nevertheless, a safety device for
this purpose is not compulsory for those special cases as agreed to between the purchaser and the
manufacturer.

Adopted 10 December 1986

© December 1987, BIS

Gr 3

BUREAU OF INDIAN STANDARDS

MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

IS: 7155 ( Part 2) -1986

3.1.6 Certain fixed or mobile appliances may include an articulated or mobile part in a vertical plane,
actuated by a motor or manually; in which case, there shall be a compulsory safety device for
immobilizing such an articulated part in the event of voluntary or accidental stoppage of the motive
power even if the later is manual.

3.1.6.1 The lowering and raising system shall be fitted with a safety device to prevent accidental
lowering or lifting of the boom, and to prevent kickback of any manually operated crank.

3.1 .6.2 The device for lowering and raising the movable part shall be so located that there is no
necessity for the operator to be under the conveyor for operating the device.

3.1.6.3 The movement shall be limited at the extreme positions, by stops capable of supporting
the stress due to the load.

3.1.7 In cases of manual loading and/or unloading, the characteristics of the unit (height, width,
speed, etc ) shall be suitable for the working stations.

3.1.7.1 Mechanical devices shall be installed for:

a) the loading and unloading of unit loads exceeding 50 kg,

b) the loading of unit loads when the vertical speed exceeds 5 m/s, and

c) the unloading of unit loads when the vertical speed exceeds 025 m/s.

3.1.8 The in-running nips and pinch points of the conveying device ( belts, chains, belt pulleys,
etc ) and the movable parts ( chain sprockets, spur gears, couplings, etc ) shall be protected.

3.1.9 When shearing and squeezing points or zones exist on the path of the conveying element
(for example at a change of direction, or the close approach to fixed parts, etc), guards shall be
provided.

3.1.10 All movable parts giving access through mechanical handling equipment shall be designed
so that they cannot be opened whilst the apparatus is working and so that the appliance cannot be
used or started while they are 'open'.

3.1.11 The loading and unloading openings of the enclosed units ( in casing or in housing ) shall be
made in such a way that they prevent access to the moving components; otherwise suitable protection
shall be provided.

3.1.12 Openings in enclosed appliances, which give access to moving parts, shall be guarded by
covers which require a hand tool for removal or are locked or are interlocked with the drive to the
equipment. Cover which it is necessary to open while the appliance is in operation shall expose a
suitable fixed grating, which shall prevent access.

3.1.13 Access to inspection holes shall be easy.

3.1.14 All the lubrication points used frequently shall be accessible without it being necessary to
remove the guards.

3.1.15 It is recommended that equipment be so designed that cleaning is facilitated.

3.1.16 Equipment mounted on a moving frame, or any other additional equipment, such as the
loading chute, feeders, etc, whether they are self-propelled or hand-operated, shall be provided with
a device enabling them to be immobilized.

3.1 .1 6.1 Safety devices shall be provided to limit the travel of such equipment.

3.1.17 Wheels or rollers of travelling conveyors and of additional travelling equipment shall be
guarded at points accessible to personnel under normal working conditions.

3.1.18 Whenever an operator remains on the travelling equipment, a platform shall be provided and
be so designed as to prevent any accidental contact with mobile components or any part of the fixed
installation.

3.1.19 When mobile appliances or equipment travel alongside an unprotected gangway, warning
devices shall be provided.

IS :7155 ( Part 2 ) -1986

3.1 .20 Sharp edges and corners shall be avoided.

3.1.21 The projecting parts of moving equipment shall be as small as possible.

3.1.22 Overhead gentry portion of road and rail crossings, walkways, gallaries, work places under
the overhead conveyors used by the personnel, shall be protected by means of suitable covering such
as plates/steel sheet covers to prevent falling of the material/objects over such areas/personnel.

3.2 During the Installation Stage ( Layout, Erection and Entry into Service )

3.2.1 All powered appliances or complete installations shall carry the following indications
permanently and legibly marked in a clearly visible place:

a) Name of the manufacturer or the supplier, and

b) Year of manufacture and serial number.

3.2.2 Access to Conveyors — Permanent platforms shall be provided from which all parts of the
plant which need to be reached for the purpose of operation, regular servicing and maintenance are
regularly and safely accessible. A clear access platform or floor space of at least 0'50 m width shall
be provided for the maintenance of every driving mechanism. All service platforms of appliances and
cabins on which operating personnel may be required to be stationed should remain horizontal.

3.2.3 All gangways, staircases, steps or platforms provided shall offer a minimum passageway of
0'50 m- They shall be protected on the .open side by guard-rails composed of a hand-rail normally
1 m above the walkway, a knee-rail and a toe-guard, or by an equivalent plain sheeting. In the case
of gangways inclined more than 5°, a suitable non-slip surface to avoid slippage/skiding shall be
provided with uninterrupted vertical sheeting on the side remote from the moving appliance. A hand-
rail shall be provided on this side. To avoid the risk of trapping by a moving device, the height of the
hand-rail can be modified to not less than 0*80 m above the walkway so as to ensure a minimum
clearance of 0'50 m between the appliance and the hand-rail.

3.2.3.1 Access between movable parts of static appliances, or the load that they carry and fixed
obstacles, shall be prevented by guards when the free space is less than 0'50 m.

3.2.3.2 Access between the preset path of mobile appliances and fixed obstacles shall be
prevented by guards when the free space is less than 0'50 m.

3.2.4 There shall be fixed access to platforms, floors, or similar constructions located more than
1*50 m above ground level.

3.2.4.1 Platforms at different levels shall be adequately and conveniently connected by stairways
or where stairways are not practicable, by fixed ladders. It is recommended that ladders be avoided as
a means of access and access shall preferably be by a sloping ramp with slats, or by a staircase. The
angle of staircases in relation to the horizontal shall not exceed 60°.

3.2.4.2 If a ladder has to be used, the width between the uprights shall be 0'35 m minimum; on the
access side, the free space between the ladder and any continuous obstacle shall be 0*60 m minimum;
this free space may be reduced to 0'40 m near a localized obstacle of small width; on the opposite
side, the free space between the ladder and any obstacle shall be 0*20 m minimum. When the ladder
is put vertically or at an angle equal to or greater than 70° and its vertical height is equal to or greater
than 5 m, a protection (crinoline, guard or other device) shall be provided commencing 2 m from the
starting level.

3.2.4.3 Suitable landings or resting places, where practicable, shall be provided if agreed to
between the purchaser and the manufacturer.

3.2.4.4 Access to plant for purposes of operation shall be from floors and platforms and not from
stairways or fixed ladders. Portable ladders shall not be used as places from which operation or regular
servicing may be carried out. However, their use may be permitted for occasional maintenance in
situations not exceeding 3 5 m in height. Where the height exceeds 3'5 m up to a maximum of 6 m,
other suitable means such as an approved mobile work platform or a tower ladder may be used
provided adequate access is available for their use and to enable placement with ease.

3.2.4.5 Where walkways are provided on both sides of a conveyor and where convenient access
to either side of the conveyor may be required by employees, who regularly work in the area, crossovers

IS: 7155 (Part 2) -1986

shall be provided at appropriate intervals andattheheadandtailendsoftheconveyorswhere.no
other crossing is available. Safe means of access shall be provided at crossovers.

3.2.5 All flooring of platforms or gangways and treads of staircases and stops shall be selected to
suit individual installations and working conditions, and shall have a non-slip surface.

3.2.6 It is recommended that sharp edges and corners be avoided in the areas normally accessible
to personnel between the floor and a height of 2 m.

3.2.6.1 This recommendation need not be followed if such edges and corners are protected.

3.2.7 In case where the clearance beneath the appliances, at a passageway, is less than 1 '90 m,
it is recommended that access be by means of a gangway running over the appliance.

3.2.8 Ail authorized passageways, protected if necessary, shall be indicated in a clear manner.

3.2.9 In cases where appliances which penetrate into a pit or extend through floors leave openings,
the latter shall be protected by guard-rails and toe-guards.

3.2.10 Where appliances pass above work stations or passageways, suitable protection shall be
provided against accidental dropping of conveyed materials.

3.2.11 Conveyer control — Except where the conveyor is under the control of an operator, electrical
and/or mechanical devices shall be provided on all conveyor systems to automatically stop a conveyor
or the load when the conveyor, bin, or hopper to which it feeds, has been stopped or has been
blocked with load so that it cannot receive additional load or material. This requirement may also be
applicable to chutes for special applications and if agreed to by the manufacturer and the user at the
time of enquiry or order.

3.2.11.1 Sequence interlocks shall be provided so that no mechanical handling appliance can
supply another appliance which is inoperative or has reached its full capacity.

3.2.12 All starting and stopping devices shall be clearly indicated and easily accessible and shall be
in accordance with the requirements of IS: 4237-1982 'General requirements for switchgear and
controigear for voltage not exceeding 1 000 V.

3.2.12.1 Instantaneously operating manual stop-lock devices shall be provided either conti-
nuously or at selected points along the installation. Resetting of these devices shall be carried out by
authorized personnel and only after the fault has been rectified.

3.2.12.2 Pull cords — The conveyor system shall be provided with stay-put type pull cord
switches at suitable intervals along the conveyor so that any particular conveyor may be stopped from
any position and in case any sequential operation is intended, the conveyor in sequence may also be
stopped automatically. In case of sequential interlock system, zero speed switch and belt sway
switch shall also be provided.

3.2.13 When an appliance extends out of sight of the control station operator, audible and/or
visual signals shall be provided to warn personnel that the starting of the appliance is imminent.

3.2.14 Ail starting and stopping devices shall be clearly indicated and easily accessible. It is
recommended that they be painted to a specified pattern.

3.2.15 It is recommended that all lubrication points be painted to a specified pattern.

3.2.16 Gangways, hand-rails, staircases, ladders, guards, etc shall be erected before the installation
is put into service.

3.2.17 The feeding and discharge controls, either manually or mechanically operated, shall be
easily accessible. They shall, where necessary be placed so as to permit supervision of the flow.

3.2.18 The openings of feeding or transfer hoppers and chutes shall be guarded if normally
accessible to personnel. It is recommended that inspection doors be provided on large hoppers and
chutes.

3.2.19 Counterweight tension devices shall be guarded at points normally accessible to personnel.
Guards shall prevent access to the space directly below the counter-weight; in the absence of these
guards, sustaining devices shall be provided, giving a clearance of at least 2*5 m above ground or
other operating level.

IS : 7155 ( Part 2) - 1986

3.2.20 All loading, unloading and transfer points shall be designed so as to prevent, as far as
possible, the product or objects being conveyed from escaping, at these points or any other points
along the conveyor route. Also, for personnel employed at a loading, unloading work station transfer
of passage point adequate safeguards in the form of guard rails fences or close fitting guards shall be
installed to prevent injury to personnel.

3.2.21 Principles of guarding — Guards shall be designed to prevent injury to persons and shall be
provided at every dangerous part of a conveyor.

3.2.21.1 Guards shall be planned into the design of the conveyor or conveyor system and shall
neither be added as an after thought nor themselves provide a hazard. Guards shall not have to be
removed for normal cleaning, lubrication or belt and chain tension adjustments.

3.2.21.2 At points aiong a conveyor where material is iikeiy to become dislodged and in failing
become a hazard to persons, suitable guards or nonreturn flaps shall be provided.

3.3 During the Utilization Stage ( Operation and Maintenance )

3.3.1 No continuous mechanical handling equipment shaii be used for duties other than those for
which it is designed nor under conditions other than those stated in the contract of the concerned
parties and in the installation and maintenance booklets.

3.3.2 The user shall be careful to ensure a regular feed, avoiding over-loading. In particular, the
user shall not change the feeding points, particularly not their position, or increase the flow, without
previously consulting the manufacturer/constructor.

3.3.2.1 Clear operating instructions concerning the loading of the appliances shall be prominently
displayed adjacent to the loading positions : they shall include the permissible unit load, its positioning
and its limiting dimensions.

3.3.3 it shaii be strictly forbidden to use continuous mechanical handling equipment for conveying
people, unless it has been specifically designed for that purpose and meets the special requirements
laid down in connection with the conveyance of people.

3.3.4 Continuous mechanical handling equipment, particularly its conveying elements, shall be
kept in proper working condition as recommended by the manufacturer and shaii be weii maintained
at all times.

3.3.4.1 Ail loading and working stations and the passageways shall be kept clear and clean.

3.3.5 The inspection, adjustment, maintenance and cleaning of moving parts ( beits, pulleys and
idlers, chains, sprockets, etc ) and of cleaning devices shall be carried out regularly according to the
manufacturer's instructions.

3.3.5.1 The frequency of these operations shall depend on the nature of the conveyed materials.
With the exception of automatic cleaning, or in the case of special devices designed to aiiow cleaning
while the equipment is in operation, these operations shall only be undertaken when the equipment
is at rest, and after rendering the starting devices inoperative.

3.3.6 No inspection hole shall be opened while the appliance is in operation unless it complies
with rule 3.1.11.

3.3.7 No one. except those so authorized, shall operate or interfere with the normal working of the
plant; in particular, all starting operations shall be carried out by qualified and competent personnel
only.

3.3.8 Normal and emergency stopping devices shall be made known to all personnel and be easily
accessible; all areas giving access to them shall be kept clear of obstacles s Their proper working shall
be periodically checked.

3.3.9 All restarting operations on an appliance which has been inoperative because of an emergency
or accidental stoppage shall be preceded by an inspection aiming at:

a) determining the cause of the emergency or accidental stoppage, and

b) repairing the fault.

3.3.10 It shall be strictly forbidden to cross over or under an appliance except at the points specially
provided for the purpose.

IS: 7155 (Part 2) -1986

3.3.11 All adjustments, whether mechanical or electrical, shall be carried out by competent and
authorized persons, particularly in the case of safety devices-

3.3.12 Repairs and removal of protective enclosures or panels, shall only be carried out after
stopping the equipment and after starting devices have been rendered inoperative, by a competent
person appointed for that purpose.

3.3.12.1 Recommissioning shall be carried out only after the protective devices have been replaced
and an order received from the authorised responsible person.

3.3.13 It shall be forbidden to carry out any lubrication while an appliance is in operation, except
in cases where the parts to be lubricated are so located or there are special devices which will permit
their lubrication without danger.

3.3.13.1 If, for lubrication purposes, it is necessary to remove or to open guards, lubrication shall
only be carried out with the equipment rendered inoperative as stated in 3.3.12.

3.3.14 A log-book shall be kept for each appliance and/or for each installation.

3.3.15 Suitable training (with particular reference to the operating and maintenance booklets) shall
be given to a continuous mechanical handling equipment personnel, both operating and carrying out
maintenance, as in the long run this may serve as the best form of accident prevention.

3.3.16 The user shall not make alternations which affect the design, construction, installation or
handling requirements of the appliances without the consent of the manufacturer constructor and/or
the contractor, as some alterations may give rise to detrimental consequences.

3.3.17 Inspection and adjustment of continuous mechanical handling equipment, in motion or in
use, shall only be carried out with guards in position unless it is impracticable for the said operations
to be carried out other than with the guards removed. If the guards are removed, such removal shall
be restricted to the immediate area involved, taking all necessary precautions and especially forbidding
any approach to nip points.

3.3.18 If the area where guards are removed is situated in a working area or where personnel walk,
such an area shall be fenced off to prevent personnel approaching it when the appliance is in motion.

3.3.19 When guards are not in position, and the appliance is in motion, work shall only be done
from a stable standing place. If a ladder is required, it shall be secured in position or firmly held by
another person(s).

3.3.20 When guards have been removed from continuous mechanical handling equipment in motion,
work shall only be undertaken by personnel authorized and well acquainted with the risks associated
with machinery in motion. Such personnel shall wear close-fitting overall with no loose ends,
preferably made in one piece.

3.3.21 If work has to be carried out on unfenced machinery in motion, another person(s), well
acquainted with the actions to be taken in case of emergency shall keep watch on the person at work,
and hold himself close to and ready to operate a stop device.

EXPLANATORY NOTE

IS: 7155 as code of practice for conveyor safety was published in 1974. Based on the
experience gained in the field and revision of related International Standards as also the availability
of some other related ISOs, this revision has been taken up.

This part 2 of the standard is one of the series of Indian Standard code of recommended practice
for conveyor safety. The other parts of the standard are:

Part 1 General information, and

Part 3 Belt conveyors and feeders.

Part 1 of the standard is a necessary adjunct to other parts of this standard.

In the preparation of this standard, considerable assistance has been derived from the following
publications:

ISO 1819-1977 'Continuous mechanical handling equipment — Safety code — General
rules' issued by the International Organization for Standardization (ISO);

ISO 7149-1982 'Continuous handling equipment — Safety code — Special rules' issued by
the International Organization for Standardization (ISO); and

AS CZ 15-1971 'SAA Conveyor safety code' issued by the Standards Association of Australia.

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