Agriculture Reference
In-Depth Information
The carcase splitting saw station usually requires a
'rise and fall' platform equipped with a saw steriliser for
use between carcases. It is important to attempt to con-
tain the sawdust from the bandsaw by using a ceiling to
floor stainless steel screen and a 'sock' to contain the
effluent from the integrated saw blade wash.
Intermittent powered system
This system can be used for rates of 10-75 cattle/hour. It
involves the mechanical moving of the carcases sus-
pended on a spreader (gambrel) and trolley along a level
rail at intervals by means of a variable timing device
which can be pre-set to suit the slaughter rate.
On-the-rail dressing
The development of
line dressing
of carcases originally
emanated from Canada. Essentially, the carcase is con-
veyed by gravity or power along an overhead rail; after
stunning and bleeding, the process of dressing is divided
up into various stages, each undertaken by a separate
operator as the carcase reaches him. Although some
establishments use the traditional one man-one job
approach, a better approach is to allow one operative to
follow the carcase through several operations. Besides
reducing the labour load, this arrangement also makes
for better job satisfaction and gives the opportunity to
build in an apron, equipment wash and knife sterilisation
step. A combination of several machines, tools and cor-
related items of equipment (brisket saw, hock cutters,
hide puller, aitch bone cutter, etc.) enables complete
dressing to be carried out at high rates of slaughter. Use of
robotics, especially for pig slaughter, has been developed,
but cost of installation and difficulties with the quality of
dressing have hampered their widespread introduction.
Several systems of line dressing are in operation, the
type depending mainly on the level of throughput,
equipment design and species, being most complicated
in cattle. Ideally, the dressing line should be as straight as
possible so as to physically separate by a maximum dis-
tance the dirty hide on carcase from the clean dressed
one. A straight line also permits the hygienic removal of
waste and by-products to rooms located parallel to the
slaughter line.
There are four main types of line dressing for cattle.
Continuous powered system
In this method, the dressing line is in continuous motion
and is used for higher rates of kill, 40-120 cattle/hour.
More sophisticated equipment is associated with this
slaughter line, for example, mechanical hide puller
and moving-top inspection table as with the 'Canpak'
system.
The carcase can be revolved a full 360° while on the
rail, allowing the operator to work all sides from one
position. Associated with all line systems are platforms
which can be varied in height and position, enabling the
operator to carry out his task more efficiently.
'Canpak' system
This is a continuous conveyorised method in which the
carcases are suspended by heavy beef trolleys or runners
from the overhead rail; no spreader or gambrel is used.
Developed and patented by Canada Packers Ltd.,
Toronto, Canada, it is probably the most common form
of line system now used in large modern meat plants.
Rates of slaughter from 50 to 150 cattle or more per hour
can be achieved depending on the type and extent of
associated equipment and the number of operators.
A typical sequence of operations on a modern line
system is shown in the beef slaughter flow chart in
Figure 3.5. In the United Kingdom, a number of
additional tasks are carried out to remove the bovine
specified offals and to check their removal.
Advantages of line dressing
Gravity rail system
In this method, the carcases are suspended from a
spreader and single-wheel trolley or runner, transferred
by gravity to each station and stopped by a manually
operated stop on the overhead rail.
The system is used for lower slaughter rates of 10-40
cattle/hour. It is probably the most compact and eco-
nomical of the systems. Being the simplest in design,
there is less chance of serious breakdowns with conse-
quent loss of production. Various items of equipment
may be used with the gravity rail, for example, a moving-
top viscera inspection table or a paunch truck, but
because throughput is small, a mechanical hide puller is
rarely used. Adequate ceiling height is necessary because
of the pitch of the rail to gravitate the carcases.
1
Since carcases are conveyed to each dressing station,
there is no need for operatives to be idle while carcases
are being hoisted or positioned.
2
The line system is said to be safer for operatives than
traditional slaughter systems.
3
Because carcases do not touch the floor and their
dressing is more conveniently carried out, 'on-the-rail'
dressing is hygienic.
4
Elimination of the handling of heavy shackles, trolleys
and spreaders; the use of comfortable platform posi-
tion for personnel; and the use of mechanical tools
reduce tedious labour.
5
An efficient line system increases throughput and may
enhance the value of the carcase, hide and offal
because of superior workmanship.
