HOPPER GUARDS FOR CONCRETE READY-MIX
              TRUCKS IN USE ON CONSTRUCTION PROJECTS


Produced by:
Construction, Health and Safety Program,
Ontario Ministry of Labour
Alert #C10/0895
ISSN 1195-5228

After a review of the matter, the Ministry of Labour has certain 
recommendations about hopper guards for concrete ready-mix trucks 
in use on construction projects.

On concrete ready-mix trucks, the hopper that feeds raw material 
into the mixing drum consists of an upper, vertical part and a 
lower, nearly horizontal part that extends into the drum.  Thus, 
when the drum is in operation, its mixing blades are rotating 
around the lower part of the hopper.  Between the blades and the 
lower part of the hopper there is a gap, which, because of the 
blades' spiral shape, varies in size as they rotate.

A worker is not routinely near this gap.  However, for certain 
tasks, such as making a visual check of the concrete's 
consistency, a worker will stand on the ladder platform while the 
drum is rotating.  There may be a risk of injury to a worker in 
this position.

The Ministry of Labour recommends:

1.  Firms should review all ready-mix concrete trucks they have 
    in use and, where practicable, provide a guard that restricts 
    access to the part of the gap described above to which access 
    might otherwise be possible for a worker on the ladder 
    platform. 

2.  Any manufacturer of ready-mix concrete trucks not already 
    doing so should include such a guard on all future models as 
    original, factory-installed equipment. 

This Alert has been developed in co-operation with the Ready-Mix 
Concrete Association of Ontario (365 Brunell Road, Unit #3, 
Mississauga, ON  L4Z 1Z5).  Enquiries should be directed to the 
Association at (905) 507-1122.