Roll-on/roll-off
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Loading a ro ro passenger car ferry Roll-on/roll-off (RORO or ro-ro) ships are ferries designed to carry !heeled cargo such as automo"iles, trucks, semi trailer trucks, trailers or railroad cars# $his is in contrast to lo lo (lift on lift off) vessels !hich use a crane to load and unload cargo# RORO vessels have "uilt in ramps !hich allo! the cargo to "e efficiently %rolled on% and %rolled off% the vessel !hen in port# While smaller ferries that operate across rivers and other short distances still often have "uilt in ramps, the term RORO is generally reserved for larger ocean going vessels# $he ramps and doors may "e stern only, or "o! and stern for &uick loading#
$he Pride of Burgundy, a '(O Ferries passenger car ferry on the )over *alais +nglish *hannel route !hich can carry ,-- cars#./0 1arious types of RORO vessels include ferries, cruiseferries, cargo ships, and "arges# 2e! automo"iles that are transported "y ship around the !orld are often moved on a large type of RORO called a 'ure *ar *arrier ('**) or 'ure *ar $ruck *arrier ('*$*)# 3nlike else!here in the shipping industry !here cargo is normally measured "y the metric tonne, RORO cargo !ill typically "e measured in the more convenient unit of lanes in meters (L45s)# $his is calculated "y multiplying cargo length in meters "y the num"er of decks and "y its !idth in lanes (lane !idth differs from vessel to vessel and there are a num"er of industry standards)# 6"oard '**s cargo capacity is often measured in R$ or R$78 units !hich is "ased on a /9,, $oyota or "y car e&uivalent units (*+3)#
$he largest RORO passenger ferry is 5: Color Magic, a ;<,/-- =$ cruiseferry that entered service in :eptem"er >--; for *olor Line# ?uilt in Finland "y 6ker Finnyards, she is >>8#;- m (;88 ft // in) long, 8< m (//7 ft /- in) !ide and can carry <<- cars as !ell as />;lane meters of cargo#.>0 $he RORO !ith the greatest car carrying capacity is the Ulysses (named after a novel "y James Joyce) !hich is o!ned "y 4rish Ferries# :he entered service on >< 5arch >--/ and operates "et!een )u"lin and @olyhead# $he <-,98A =$ ship is >-9#-> m (,A< ft 9 in) long and 8/#A7 m (/-7 ft , in) !ide, and can carry /87> cars and 7/-/ lane meters of cargo#.80
History
6t first, !heeled vehicles carried as cargo on oceangoing ships !ere treated like any other cargo# 6utomo"iles had their gas tanks emptied and their "atteries disconnected "efore "eing hoisted into the shipBs hold, !here they !ere chocked and secured# $his process !as tedious and difficult, vehicles !ere su"Cect to damage, and could not "e used for routine travel# )uring WW44, landing craft !ere also among the first seagoing ships ena"ling road vehicles to roll directly on and off# 'ost !ar, the idea !as adopted for merchant ships and short ferry crossings# $he first RoRo service crossing the +nglish channel "egan from )over in /9<8# 4n /9<; the 3: military issued a contract to the :un :hip"uilding and )ry )ock *ompany in *hester, '6 for the construction of a ne! type of motoriDed vehicle carrier# $he ship, Comet, had a stern ramp as !ell as interior ramps !hich allo!ed cars to drive directly from the dock, onto the ship, and into place# Loading and unloading !as speeded dramatically# Comet also had an adCusta"le chocking system for locking cars onto the decks, and a ventilation system to remove any eEhaust gases that accumulated during vehicle loading# 6 PCC shipFs star"oard side sho!ing side ramp :ince /9;- the market for eEporting and importing cars has increased dramatically and the num"er and type of ROGROs has increased also# 4n /9;8, JapanBs H Line "uilt the European Highway, the first 'ure *ar *arrier ('**), !hich carried 7,>-- automo"iles# $odayBs pure car carriers and their close cousins, the 'ure *arG$ruck *arrier ('*$*) are distinctive ships !ith a "oE like superstructure running the entire length and "readth of the hull, fully enclosing and protecting the cargo# $hey typically have a stern ramp and a side ramp for dual loading of many thousands of vehicles, as !ell as eEtensive automatic fire control systems# $he '*$* has lifta"le decks to increase vertical clearance as !ell as heavier decks for %high and heavy% cargo# 6 ,<-- unit car ship !ith /> decks can have three decks !hich can take cargo up to /<- tons !ith lifta"le %panels% to increase clearance from /#; meters to ,#; meters on some decks# Lifting decks to accommodate higher cargo reduces the total capacity# With the "uilding of the Wallenius Wilhelmsen LogisticsFs A--- *+3 car carrier Faust, out of :tockholm, in June >--; the car carriers entered a ne! era called the L*$* (Large *ar ( $ruck *arrier)#.70
Risks
$he seagoing RORO car ferry, !ith large eEternal doors close to the !aterline and open vehicle decks !ith fe! internal "ulkheads, has a reputation for "eing a high risk design (to the point !here the acronym is sometimes derisively eEpanded %Roll OnGRoll Over%.<0)# 6n improperly secured loading door can cause a ship to take on !ater and sink, as happened for eEample in /9A; !ith the Herald of Free Enterprise# Water sloshing on the vehicle deck can set up a free surface effect making the ship unsta"le and causing it to capsiDe# Free surface !ater on the vehicle deck !as determined "y the *ourt of 4n&uiry to "e the immediate cause of the /9,A capsiDe of the ahine in 2e! Iealand .,0#
Benefits
While the characteristics of seagoing RORO car ferries have inherent risks, there are "enefits to its sea!orthiness# For eEample the car carrier Cougar !ce listed A- degrees to its port side in >--, "ut did not sink, since its high enclosed sides prevented !ater from entering#
Variations of RORO
ROPAX
$he acronym ROPAX (roll onGroll off passenger) descri"es a RORO vessel "uilt for freight vehicle transport "ut also !ith passenger accommodation# $echnically this encompasses all ferries !ith "oth a roll onGroll off car deck and passenger carrying capacities, "ut in practice ships !ith facilities for more than <-- passengers are often referred to as cruiseferries#
ConRO
$he ConRo vessel is a hy"rid "et!een a RORO and a container ship# $his type of vessel has a "elo! decks area used for vehicle storage !hile stacking containeriDed freight on the top decks# +Eamples of *onRo ships such as those in the fleet of 6tlantic *ontainer Line can carry a com"ination of /,9-- t!enty foot e&uivalent units ($+3s) of containers, up to /,--$+3s of heavy e&uipment, as !ell as proCect and oversiDed cargo on three decks and up to >,--- automo"iles on < decks# :eparate internal ramp systems !ithin the vessel segregate automo"iles from other vehicles, mafi trailers and "reak"ulk cargo#
RoLo
6 RoLo (roll on lift off) vessel is another hy"rid vessel type !ith ramps serving vehicle decks "ut !ith other cargo decks accessi"le only "y crane#
