are ramps built to connect rivers to river banks or
seas to sea shores. They allow boats and barges to get
in or out of water. Such small vessels are first moved
down slipways during inauguration. Once in a while,
they are moved upwards for repair, maintenance or overhauling
purposes and then moved downwards when ready to go back
into service. Efficient slipway operation calls
for the use of appropriate machinery with adequate design
and sufficient safeguards. The right slipway machinery
must provide the target lifting capacity, suit the site
topography and ensure safe vessel handling.
appropriate slipway machinery was needed to operate
a slipway located at Shobra El Kheima; a north-eastern
Cairo suburb overlooking The River Nile. Due to the
narrow river bank at the location, longitudinal vessel
movement was not feasible and boats and barges had to
be laterally moved up or down the slipway. Coping with
these requirements, our design team came-up with an
effective solution for a range of vessel size and weight.
Design work was solely carried out by DMMAS.
We partnered with The
Arab Contractors ; one of the leading construction
companies in the Middle East and Africa ; to manufacture
a 200-Ton Capacity slipway machinery.
cradles are mounted on bogies to move along rails. Provided
with 4 bogies and 8 wheels, each cradle is pulled along
a separate pair of rails by a 600-meter wire rope wound
at its free end over a separate drum. Power is provided
by a 75 KW electric motor. The slipway keeps an 8-degree
inclination to the horizontal. The 3 pairs of rails extend
for 40 meters along the slipway keeping a 15-meter center-distance
between adjacent pairs. Rails are welded in a strong steel
structure fixed to a concrete block laid over compact
rocks and protected with sheet piles. Pulleys provide
90-degree wire rope redirection. Drive and controls are
secured in a control room.
go under water, carry vessels, move them up the slipway
and reverse this process when the repair work is over. Three
drums work separately; each controlling a cradle. So, the
working load can be increased to double or triple a single
cradle capacity. The vessel size changes accordingly. The
load carrying capacity of each cradle is 70 tons. Three
operational situations are possible. One drum can be operated
to lift a 70-ton small boat. A small 40-meter long 140-ton
heavy barge requires the operation of two drums. Large barges
of up to a length of 55 meters and a weight of 200 tons
can be lifted through 3-drum operation.
operation is guaranteed and enough security measures are
taken. Power ranges from 46 KW to 75 KW. Speed varies
from 750 RPM to 1500 RPM. Cradles move at a speed ranging
from 2 meter/min to 4.4 meter/min.The electric motor is
provided with electro-magnetic brakes. Additional hand
brakes are available. Programmable logic controllers are
used to secure operation.
machinery may be adopted to operate different slipways.
The design of slipway machinery is not as straightforward
as it might seem. It requires knowledge, experience and
vision. You may be in the process of building a slipway
to repair small vessels traveling along some local waterway.
A good idea is to get some expert consultation. Just brief
us about your project. We are ready to provide advice.
We are even ready to supply the machinery necessary to
operate your slipway in the most effective and efficient