Denith Engineering was appointed for the design, manufacture and supply of two Roll-on/Roll-off (Ro-Ro) ramps for the Temporary Beach Landing to be used for the construction of a new Liquefied Natural Gas (LNG) project in Mozambique.
There are two identical ramps adjacent to each other. Each ramp has an internal clearance of 5500mm and overall span of 19500mm. The ramps are modular, and each comprises a base frame fixed to a concrete slab at a lower level to the jetty and a ramp, pivoted at the jetty side. The Base is made primarily of column section and hollow round bar for the main pivot joint and hydraulic cylinder pickups. The ramp is a welded plate structure with bars welded on the traffic surface for additional grip. On either end of the ramp are pivoted landings, one landing will rest on the barge whilst the other on the jetty.
The ramp is actuated vertically using marine quality hydraulic cylinders and will allow for the various movement and torsion from both the barge as well the offloading vehicles. During operation the ramps are supported on the barge while the hydraulic lifting system is set to free floating mode. In this respect the ramps are similar to a ships ramp or the fingers provided at the end of a supported link span.
The Ro-Ro Ramps are primarily designed for offloading aggregate from Barges using Articulated Dump Trucks (ADT’s) at all states of tide between MLWS and MHWS. The design vehicle is a CAT 740B with MGW of 74 Tonne. The Ro-Ro ramps are not wide enough for bi-directional traffic and only single vehicle loadings were considered as queuing on the ramps will not be allowed.
The base frame of the Ro-Ro ramp is designed to operate in a semi-submerged state in sea water during certain periods of operation and as such is provided with anodic protection and painted as per the client specified coating procedure.