A roll trailer or "Mafi" is a
trailer platform that requires towing by a
powered vehicle. It is commonly used for the transport of heavy static goods and materials in the maritime shipping industry. Roll trailers are similar to shipping
flat racks containers, however, they have a set of rear wheels.
Overview
Roll trailers are a common equipment used in
port
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...
s and on board of
roll-on/roll-off ships, to facilitate the shipping of unmovable commodities and
oversize load from one port to another.
Standard lengths of roll trailers are , in line with
twenty-foot equivalent unit shipping containers, but can also be found in lengths of . The standard payloads of roll trailers vary from 40 to 120 tons, and the tare of the trailer varies from 7 to 10 tons.
The
trailer has a
steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...
structure and a
hardwood
Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostl ...
surface, plus a front pocket for towing by
tugmaster gooseneck, and side handles for applying lashing hooks.
Operations
Goods are usually placed on roll trailers by
forklift
A forklift (also called industrial truck, lift truck, jitney, hi-lo, fork truck, fork hoist, and forklift truck) is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th c ...
or shore
crane, secured with lashing or chains, and then towed on/off board via tugmaster
tractor
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...
. When empty, they can be stacked like
shipping containers.
Every trailer has a unique identification number stamped on sides, composed of four letters and seven digits, directly related to the manufacturer company abbreviation name, the payload capacity and its length size.
All the main
shipping line
A shipping line or shipping company is a company whose line of business is ownership and operation of ships.
Shipping companies provide a method of distinguishing ships by different kinds of cargo:
# Bulk cargo is a type of special cargo that is ...
s have an owned fleet of roll trailers available to be offered to shippers for moving heavy static cargo.
Additionally, all main roll trailers manufacturers tend to lease extra equipment during peak times, by charging a daily hire fee to the shipping lines.
Once in the
port
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...
, after a short "free time" period, roll trailers are subject to
demurrage charges, to cover storage and detention fees
and to ensure consignees swiftly unload their cargo, temporary positioned on the shipping line's trailers during the sea passage.
As per standard practice, and opposite to shipping containers, roll trailers are not permitted to exit the ports, with receivers requested to collect their goods inside the terminals.
Shipping lines may need to move empty roll trailers to different ports. The roll trailers can be stacked on top of each other through lifting, then lashed together, and loaded onto a vessel to be taken to another port.
Gallery
File:Mafi carrying cable reels.JPG, Cable reels transport
File:Mafi carrying crate.JPG, Crate carriage
File:Tandem mafi.JPG, Tandem
Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...
operation
See also
*
Terminal tractor
References
{{Reflist
Trailers
Articulated vehicles
Freight transport
Intermodal containers