[0001] The invention relates to the field of towing ships. In particular, the invention
relates to the towing of ships which, as a consequence of calamities, such as the
failure of the main propeller, collisions or the break-out of fire on board, are no
longer able to reach a harbour under their own power. In these cases another vessel,
usually a tug, must be called for assistance to take the damaged ship under tow. To
this end, a tow rope must be transferred between ship and tug, which in most cases
is a routine matter.
[0002] As long as the weather conditions are not too severe, and/or the nature of the defects
is not too serious, no great difficulties are encountered in transfer of a tow rope.
However, this changes when the ship concerned is in an area where weather is poor
and there are high seas and, moreover, is on fire. Such a combination of factors makes
transfer of a tow rope virtually impossible, the more so in view of the fact that
the crew has by then already abandoned ship.
[0003] Especially in the case of tankers, the consequences of such emergency conditions
can be serious. Frequently the poor weather conditions and/or the heat of fires on
board force such a long delay in the operations necessary for transferring the tow
rope that the ship sinks with its cargo or founders on a nearby coast. This type of
outcome in such emergency situations is disastrous for the environment and, if the
area concerned is important for activities such as fishing or tourism, for the economy.
[0004] The aim of the invention is, therefore, to offer a solution to the problems with
regard to the towing of a vessel which is in a serious emergency situation. This aim
is achieved in that an installation is provided for running out a tow rope from a
ship or freighter, such as an oil tanker or a container ship, comprising a floating
body, which is connected to the tow rope or an auxiliary cable and is provided with
propelling means, and launching means intended to be fitted on board the ship for
launching the floating body from the ship, such that, after the floating body has
been launched, the cable can be run out with respect to the ship by means of the tensile
force delivered by the propelling means of the floating body, and can be kept in the
run-out position for a prolonged period.
[0005] According to the invention it is now no longer necessary to gain access from the
tug to the stricken ship in order to transfer a tow rope. A cable can be run out to
beyond the danger zone from the ship itself, without the intervention of crew present
on said ship. Said cable can then be picked up by a tug at a safe distance.
[0006] A command to set the installation according to the invention in operation can be
given in various ways. For example, if the installation is equipped with a launching
device which can be actuated by a receiver, use can be made of radio signals for this
purpose. The installation is then set in operation from the tug.
[0007] It is also conceivable to set the installation in operation automatically, by means
of sensors on board the ship concerned itself.
[0008] The floating body can be constructed in various ways. However, it is important that,
even in heavy seas, said floating body must be able to travel in a specific line,
in the direction away from the ship. The floating body is therefore preferably constructed
as an auxiliary vessel which also comprises steering means.
[0009] In connection with the pick-up, the auxiliary vessel carries fixing means to which
a hoisting cable from a tug can be attached.
[0010] Preferably, the floating body comprises an energy source which can supply power to
the propelling means at least for a few hours. The installation can keep the auxiliary
cable or tow rope in the run-out position for a prolonged period. This period must
be at least so long that a tug has sufficient time to sail, for example from a harbour
where it is lying ready, to the stricken ship and to pick up the run-out auxiliary
cable or tow rope.
[0011] The propelling means can comprise either a combustion engine or an electric motor,
or a combination of the two.
[0012] The invention also relates to a ship provided with the installation described above,
the launching means being installed close to the bow or the stern of the ship and
pointing obliquely downwards, such that, on launching, the auxiliary vessel can be
moved directly towards the water surface taking with it the auxiliary cable or the
rope, which rope is attached to the ship on which the launching means are provided.
The launching means can be located somewhat wide of the outermost point of the bow
or stern. It is also possible to install two sets of launching means, directed towards
different sides of the ship, at the bow or stern.
[0013] The invention also relates to the use of an auxiliary vessel, which can be launched
to sea and has an auxiliary cable or tow rope attached thereto, on board a ship or
freighter for running out the auxiliary cable or tow rope, and keeping said cable
or rope in the run-out position for a prolonged period, such that another ship, such
as a tug, can take the run-out auxiliary cable or tow rope on board in order to tow
the first ship.
[0014] A floating body which is provided with propelling means and can be launched from
a platform erected in the sea is disclosed in "Ship & Boat International", Part 41,
No. 1, January 1988, Worchester Park, pages 19-20, "Getting Clear". The purpose of
the launched floating body is to pull a lifeboat lowered into the water from the platform
away from the vicinity of said platform as quickly as possible. The energy source
of the propelling means is exhausted after a few minutes. Within this period the lifeboat
has been towed a sufficient distance away from the platform to enable it to sail further
under its own power.
[0015] This known installation is not suitable for running out a tow rope from a stricken
ship, or for keeping the tow rope or auxiliary cable in the run-out position for a
sufficiently long period such that a tug would be able to pick up the rope.
[0016] The invention will be explained in more detail below with the aid of the illustrative
embodiment shown in the figures.
[0017] An installation according to the invention, which is indicated in its entirety by
2, is installed on board the ship 1, only part of which is shown in the figure. Said
installation 2 comprises mounting means 3, which are constructed as a tubular housing
in which an auxiliary vessel 4 is housed. Said auxiliary vessel 4 is secured with
respect to the mounting means 3 in a known manner.
[0018] Launching means, which are known per se, are also provided. Said launching means
comprise the rails 5, which are shown diagrammatically and extend to either side of
the auxiliary vessel 4 in the mounting means 3. It is also possible to provide a drive
charge, by means of which the auxiliary vessel 4 can be shot out of the mounting means
3 over the rails 5.
[0019] The auxiliary vessel 4 is connected to a cable 6, which is wound on a reel 7.
[0020] If the ship gets into an emergency situation, the auxiliary vessel 4 can be shot
out, pulling the cable 6 with it. When it is shot out, the auxiliary vessel makes
a free fall, passing through the positions indicated by 8 and 9.
[0021] The auxiliary vessel becomes submerged, comes up again and then floats on the surface
of the water as shown at 10.
[0022] In the meantime, the propeller installation of the auxiliary vessel 10, which installation
is indicated diagrammatically by 11, has been set in operation, such that the auxiliary
vessel sails away from the stricken ship 1, taking cable 6 with it.
[0023] To ensure that the auxiliary vessel sails in the right direction, that is to say
away from the ship 1, and also, in the event of the vessel foundering, away from the
coast, steering means 12, which are known per se and are also indicated diagrammatically,
are provided.
[0024] The auxiliary vessel sails further and further away from the ship 1, until the entire
cable 6 has been unwound from the reel 7. However, the propeller device 11 of the
auxiliary vessel continues to operate, so that the cable 6 is continuously held in
its position, pointing away from the ship 1.
[0025] The auxiliary vessel is sufficiently large to carry a substantial energy source,
so that such a position can be maintained over several hours. In the intervening period
a tug is able to approach the auxiliary vessel 4 and pick it up by means of the fixing
points 13.
[0026] After the auxiliary vessel 4 has been taken on board a tug, the cable 6 can be pulled
in by the tug and, where necessary, a rope located on board ship 1 can be pulled to
the tug.
[0027] A lightweight cable is preferably used for cable 6, such that the auxiliary vessel
4 is well capable of dragging said cable 6 along over a fairly long distance from
the ship. Nevertheless, cable 6 can also be made sufficiently heavy to enable it to
be used itself as tow cable.
[0028] If cable 6 is a lightweight auxiliary cable, a heavier tow rope can also be wound
on reel 7. In this case means can be provided on reel 7 which allow the auxiliary
vessel 10 to unwind the relatively lightweight auxiliary cable 6 from the reel 7.
Said means must then be constructed in such a way that they allow unwinding of the
relatively heavy tow rope only if a traction force is exerted which is greater than
the tensile force which can be exerted by the auxiliary vessel 4. A higher traction
force of this type can easily be exerted by a tug, such that the tow rope is released
by the reel 7 only under the influence of traction force exerted by the tug.
1. Installation for running out a tow rope from a ship or freighter, such as an oil tanker
or a container ship, comprising a floating body, which is connected to the tow rope
or an auxiliary cable and is provided with propelling means, and launching means intended
to be fitted on board the ship for launching the floating body from the ship, such
that, after the floating body has been launched, the cable can be run out with respect
to the ship by means of the tensile force delivered by the propelling means of the
floating body, and can be kept in the run-out position for a prolonged period.
2. Installation according to Claim 1, wherein the rope or cable can be unwound from a
reel on board the ship.
3. Installation according to Claim 1 or 2, wherein the floating body is connected to
one end of an auxiliary cable, which auxiliary cable is connected at its other end
to a tow rope.
4. Installation according to Claim 1, 2 or 3, wherein the floating body is an auxiliary
vessel which also comprises steering means.
5. Installation according to Claim 4, wherein the auxiliary vessel carries fixing means
to which a hoisting cable from a tug can be attached.
6. Installation according to one of the preceding claims, wherein the floating body is
provided with an energy source which can supply power to the propelling means for
at least several hours.
7. Installation according to Claim 6, wherein the auxiliary vessel has a combustion engine
for driving a screw, as well as fuel containers having a capacity suitable for supplying
the combustion engine for at least a day.
8. Ship provided with an installation according to one of the preceding claims, wherein
the launching means are installed close to the bow or the stern of the ship and pointing
obliquely downwards, such that, on launching, the auxiliary vessel can be moved directly
towards the water surface taking with it the auxiliary cable or the rope, which rope
is attached to the ship on which the launching means are provided.
9. Ship according to Claim 8, wherein the rope is attached to the ship in the immediate
vicinity of the location where the launching means have been installed on board the
ship.
10. Ship according to Claim 8 or 9, wherein the cable is a lightweight auxiliary cable
which is connected to a tow rope located on board the vessel.
11. Use of an auxiliary vessel, which can be launched to sea and has an auxiliary cable
or tow rope attached thereto, on board a ship or freighter for running out the auxiliary
cable or tow rope, and keeping said cable or rope in the run-out position for a prolonged
period, such that another ship, such as a tug, can take the run-out auxiliary cable
or tow rope on board in order to tow the first ship.