BT Engineering Pty Ltd
Assessment of Transportable Brick Saw

Description

The BT brick saw is designed and manufactured to provide bricklayers with a safe machine to cut bricks.
Bricklayers need a machine that can cut any angle or size from bricks easily and quickly with a minimum
of personal risk.

It is very often necessary for users to cut bricks using a line marked on the brick.

The brick saw consists of a horizontal table capable of supporting building bricks, and floor tiles of any
shape or size whilst cutting. Mounted above the table is a pivoting arm that supports the motor,
drive system and horizontal shaft for mounting the diamond wheel.

The arm pivots so that the abrasive wheel can swing down in a vertical arc to cut the bricks.
The movement is effected by the use of a handle mounted on the front of the wheel bearing housing.

The horizontal table can also slide in a horizontal front to back movement for cutting.

The pivoting head can be held in the lowered position by the use of
the handle and additionally with the use of a foot pedal to facilitate the horizontal cutting.

The abrasive action of the blade generates heat and dust; therefore a water coolant system is provided.
The water flow is controlled by a button mounted in the end of the handle.

The whole machine mounts on a foldable frame that has two wheels on the rear legs, and also handles
at both the front and the back to facilitate loading and unloading from vehicles.

Designed Risk Control Measures

The machine is designed to provide good vision and unimpeded holding with the left hand, whilst effecting
the cutting with the right hand. To fulfil this requirement the machine has been designed with the main
bearing block and the belt drive mounted on the right hand side of the abrasive wheel.

The coolant flow is controlled by a button mounted on the handle and operated by the right hand thumb.
This set up enables the operator to position the cutting line with the abrasive wheel before the coolant
obscures vision. This then gives the operator a clear view on the left-hand side, which is particularly
important when cutting to a line marking, and an open area for holding the brick with the left hand.

The wheel guard covering the top half of the blade, is of substantial steel construction. The guard includes
infill pieces fixed either side of the abrasive wheel to minimise the sludge spray at the front. This guard
covers all of the wheel not required for the cutting operation.

When carrying out horizontal cutting the foot pedal is a good safety feature as it allows the operator to use
both hands to control the brick and the carriage. This also reduces muscle strain by sharing the work load
between arm and leg.

The drive belts and pulleys are fully enclosed by a robust metal fixed guard. The on/off controls are mounted
conveniently on the front of the motor. The risk of injury to the hand used for holding the brick to be cut is
increased when angular cuts are to be made. Because of this added risk BT Engineering have designed,
two jigs or cradles to facilitate safe support of the bricks when cutting angles of any type.

Hazards

The remaining risks associated with the use of this machine are as follows:

HazardInjuryRisk
Category
Abrasive wheel
Inadvertent contact whilst it is spinninglaceration1
Struck whilst cuttinglaceration1
Contact when brick moves/jamslaceration1
Muscular injury
Muscle overuse in forearm (when cutting)strain1
Locating machinestrain1
Struck by falling/tipping machinecrush1
Eyes
Particles in eyeseye injury1
Hearing
Cutting noisedeafness1

Control Measures

The hazards listed are the residual hazards remaining when the machine is used fitted with all items as
supplied.

The abrasive wheel has all of the lower half exposed to allow proper cutting and vision.
The inadvertent contact is that which occurs when a person moves and an arm is inadvertently swung in the
path of the rotating wheel. This contact would (considering the worst possibility) result in a laceration
because the wheel is circular and does not have teeth, only small slots for heat expansion.

The risk of being struck by the wheel during cutting is due to the need to place the hands near it when cutting
and also the movement of a brick when cutting. The result could be (considering the worst possibility) a
laceration.

The risk of muscle strain is always present when lifting equipment on and off trucks.
The risk of injury from a machine falling is due to the unit being top heavy and this should be considered when
carrying out this type of operation particularly on uneven terrain that is common on building sites.

The eye and hearing risks are constant and can only be dealt with by the use of personal protective equipment.

Further Risk Control Possibilities

The risk of inadvertent contact is a low risk and can be controlled by due diligence by the operator.
Any additional guarding must not interfere with the operatorís vision. It must not inhibit the action of the
wheel in both the downward cutting movement and the horizontal slide action. Additional moving guarding should
not need any actions by the operator to remain effective but be automatic in its operation. The design and
development of any additional guarding on the front of the wheel would therefore require careful consideration
to ensure that these risks are not increased or new risks added.

The risk of being struck by the wheel when holding the item to be cut could only be reduced by the use of
suitable clamping devices. Additional clamping devices would need to be carefully designed to provide suitable
holding in all cutting circumstances and not interfere with the cutting process or add other risks.

The tipping risk can be controlled by diligence on the part of the operator and suitable labelling and
instruction should be included. Information relating to the use of eye and hearing protection should also be
included in labelling and instruction manuals.

Opinion

It is my opinion that this machine has been developed with safety of the operator a major consideration.
To further enhance the safety of this machine I would recommend the development of a brick holding device to
reduce the need for the operators to have their hands close to the abrasive wheel.

R. Roberts
Machinery safety specialist
3rd June 2002



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