Roll trailer
{{Infobox machine
| name Roll trailer
| image = File:Trailer loaded on a RoRo ship.JPG|thumb|Roll trailer loading on a ship
| caption =
| classification = Unpowered vehicle
| industry = Maritime shipping
| application = Transport
| dimensions =
| weight =
| fuel_source =
| powered = No
| self-propelled = No
| wheels = Rear only
| tracks =
| legs =
| aerofoils =
| axles = 1
| components = Frame, wheels, wooden surface
| invented =
| inventor =
| examples =
}}
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 ports and on board of roll-on/roll-off ships,{{Cite web|url=https://seanews.co.uk/features/roro-ships-effective-mode-to-ship-automobiles/|title=Effective mode to ship|date=16 April 2018|website=Sea News|access-date=15 July 2019}} to facilitate the shipping of unmovable commodities and oversize load from one port to another.
Standard lengths of roll trailers are {{convert|20|,|40|and|62|ft}}, in line with twenty-foot equivalent unit shipping containers, but can also be found in lengths of {{convert|30|and|80|ft}}. The standard payloads of roll trailers vary from 40 to 120 tons, and the tare of the trailer varies from 7 to 10 tons.{{Cite web|url=https://www.ship2shore.it/en/shipping/weco-roro-s-rolltrailers-back-on-the-market_64824.htm|title=Roll trailers back on the market|date=26 June 2017|website=ShipToShore|access-date=15 July 2019}}
The trailer has a steel structure and a hardwood 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 or shore crane, secured with lashing or chains, and then towed on/off board via tugmaster tractor.{{Cite web|url=https://www.handyshippingguide.com/shipping-news/mafi-trailer-again-proves-its-worth-to-project-freight-forwarding-and-logistics-industry_5366|title=Mafi trailer again proves its worth|date=5 March 2014|website=Handy Shipping Guide|access-date=15 July 2019}} 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 lines 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, after a short "free time" period, roll trailers are subject to demurrage charges,{{Cite web|url=https://www.joc.com/detention-and-demurrage-who-pays_20070826.html|title=Detention and demurrages who pays|date=26 August 2017|website=JOC.com|access-date=15 July 2019}} to cover storage and detention fees{{Cite web|url=https://unctad.org/en/pages/newsdetails.aspx?OriginalVersionID=1959|title= Demurrage and detention charges in container shipping|date=12 December 2018|website=UN Trade and development|access-date=15 July 2019}} 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 operation