Life rafts on ships

A system for deploying life rafts from ships, wherein the life rafts are of the inflatable type and where there are stocking-like bodies for transfer of personnel from the ship to at least one of the life rafts. The life rafts are arranged in groups which are loosely connected with a common bottom frame, and where each group includes a reception raft and several evacuation rafts detachably connected with the reception raft. The bottom frame is suspended from at least one winch wire arranged from a support frame which can be moved from a parked position inside the ship's side to an operative position outside the ship's side. When the support frame is in an operative position, the bottom frame can be lowered into the water by means of the winch. The winch wires pass through sliding guides in the bottom of the reception raft and sliding guides in a known per se rescue stocking which is stretched between the support frame and the reception raft. The reception raft is automatically inflated when the bottom frame is lowered below the surface of the water, while at the same time the evacuation rafts remain afloat uninflated beside the reception raft and detachably connected with it. The evacuation rafts' inflation mechanism can be actuated manually from the reception raft as required, thus maintaining a continuous, safe escape route from the ship's deck to the evacuation rafts.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention concerns a system for deploying life rafts from ships, 
wherein the life rafts are of the inflatable type and wherein there are 
stocking-like bodies for transferring personnel from the ship to at least 
one of the life rafts. The life rafts are arranged in groups which are 
loosely connected with a common bottom frame 1, and wherein each raft 
group comprises a reception raft 2 and several evacuation rafts 3 
detachably connected with the reception raft. 
The above-mentioned bottom frame 1 is suspended from at least one winch 
wire 4 arranged from a support frame 5 which can be moved from a parked 
position inside the ship's side to an operative position outside the 
ship's side. The winch wire(s) pass through sliding guides 6a in the 
bottom of the reception raft and in sliding guides 6b in a known per se 
escape stocking 7 which is packed between the support frame and the 
reception raft. When the support frame 5 is in an operative position the 
bottom frame 1 can be lowered into the water by means of the winch 8 while 
the escape stocking is simultaneously unfolded. The reception raft is 
automatically inflated when the support frame sinks below the waterline, 
while at the same time the evacuation rafts remain floating uninflated 
beside the reception raft and detachably connected with it. The evacuation 
rafts' inflating mechanism can be actuated manually from the reception 
raft when required, thus maintaining a continuous, safe escape route from 
the ship's deck to the evacuation rafts. 
2. Description of the Prior Art 
Evacuation from ships in distress has traditionally been performed by the 
deployment of davit launched lifeboats, where all the evacuees board the 
lifeboat before it is lowered into the water. In fair weather and calm 
waters this is a relatively safe operation, which can also be used in 
situations other than emergencies, such as when disembarking passengers 
from tourist ships in areas where the ship cannot go alongside the quay. 
However, in rough seas, which is probably the case when a ship is in 
distress, the deployment of davit launched lifeboats is an extremely risky 
operation. There are several reasons for this: The lifeboats can easily be 
smashed to pieces against the ship's side when they hit the waves. If the 
davit wires are not released synchronously and at the right moment the 
lifeboats can overturn or fall into the water from too great a height. 
Stress or panic on the part of the crew or passengers can lead to critical 
misjudgements. When the boat is afloat in the water and is detached from 
the davit wires it is facing alongside and not away from the ship's side, 
thus making it difficult to manoeuvre the boat to a safe distance in time. 
In the panic, the boats can also be put into the water too soon, thus 
leaving many passengers on board or they have to spend precious time in 
finding another "vacant" lifeboat station. Or the passengers may be 
unevenly distributed with the result that some lifeboats become 
overcrowded and not very seaworthy. Finally it should be mentioned that 
all the passengers are on board the lifeboat during the actual lowering, 
so that even a minor technical mishap with only one of several lifeboats 
can have fatal consequences despite ample surplus capacity in the lifeboat 
fleet. 
Many proposals have been presented for solving these problems. For example 
so-called free fall lifeboats have been introduced, which are covered 
lifeboats with an extra strong construction and special design, which fall 
or slide in free fall out into the water and at the moment of impact 
receive a hydrodynamic force pushing them clear of the ship independent of 
the lifeboat's motor power. These lifeboats have a reduced risk of 
colliding with the ship's side, but otherwise still retain many of the 
same disadvantages as davit launched lifeboats, particularly disadvantages 
associated with the batch-type operational method and vulnerability to 
wrong handling. In addition some new hazards are introduced: It is 
extremely important that all the passengers should be securely strapped in 
before the lifeboat is dropped into the water. It can also be fatal if the 
lifeboat in free fall hits other lifeboats, people, rafts or objects in 
the water. Moreover, free fall lifeboats are heavy, expensive and 
space-consuming installations. 
In addition to lifeboats, rafts are often used. There are small rafts made 
of rigid plastic with a coil of rope round them, which are principally 
intended as buoyancy means for people who have fallen or jumped into the 
water to hold on to. There are also inflatable rubber rafts with room for 
several tens of people. These rafts can withstand the strain of almost 
unlimited impacts and will therefore not be smashed against the ship's 
side. They do not normally have any means of propulsion apart from perhaps 
some paddles with which to manoeuvre if necessary, e.g. in order to pick 
up a person in the vicinity from the water. Nevertheless rubber rafts are 
considered by very many people to-day to be a safer evacuation means than 
lifeboats. The rafts have relatively little freeboard with the risk of 
falling overboard, but they can also be supplied with tent-shaped 
canopies. 
The problem is primarily to transfer passengers and rafts safely into the 
water. There are davit launched rafts where the rafts with the evacuees 
are suspended by means of various straps on a crane wire. This can be a 
rather hazardous operation, due amongst other things to the severe effects 
of the wind on the relatively light raft during lowering, and due to the 
risk of mechanical failure in the davit crane which is constantly exposed 
to the harsh effects of the weather and the sea and which is seldom used. 
Rafts can also be thrown or dropped overboard in a packed condition and 
inflated when they hit the water. These rafts can be entered by persons 
who have arrived in the water with life jackets by some other means. For 
boats up to a certain freeboard height there have been developed 
inflatable chutes or chutes suspended in a rigid metal construction with 
flexible connection to a mustering point on the vessel's deck. The chutes 
preferably end in a reception raft in the water. There is very little 
documentation on the usefulness of such chutes in rough seas. The chutes 
place a limit on freeboard height from the point of evacuation. 
Furthermore, chutes which comprise a rigid metal construction are 
space-consuming. For the rafts which are thrown into the water in a packed 
condition, usually in rigid plastic boxes (GRP), there is also a risk of 
the GRP's hitting one another and being destroyed, or hitting people in 
the water with even more fatal consequences. 
From amongst others Norwegian patent 134291 there is known an elastic, 
spiral-shaped chute inside a closed elastic tube or "stocking", which is 
deployed from a ship's deck to a reception raft. This chute can be stowed 
together with the reception raft folded up in a protected room when it is 
not in use, and can be used from a relatively great height. One problem, 
however, is that both the raft and the sock are very vulnerable to the 
effects of wind. Another problem is how to pull evacuation rafts over to 
the reception raft and constantly hold new evacuation rafts in readiness. 
From Norwegian patent no. 149760 there is known a reticulate escape 
stocking which can be raised and lowered from a house or a container where 
it can be stored in a folded condition. An advantage with the reticulate 
escape stocking is that it is little affected by wind, and it protects the 
evacuees without preventing them from seeing out of the stocking in order 
to survey the situation. This reduces the risk of panic or refusal. 
SUMMARY OF THE INVENTION 
The object of the present invention is to further improve the known escape 
stocking-based evacuation systems from ship to raft.

DETAILED DESCRIPTION 
The system comprises principally a group of packed life rafts 3, a 
reception raft 2, a bottom frame 1 which can also act as a stabilizing 
weight, at least one foldable escape stocking 7, a support frame 5 with an 
arrangement for transfer from a parked position to an operative position 
outside the ship's side, one or more winch wires 4 and one or more winches 
8. 
The winch 8 can be mounted on the support frame 5 as in FIG. 8 or 
permanently mounted on the ship's deck as in FIGS. 1-7. In the latter case 
the winch wires 4 pass over pulleys 18a, 18b mounted on the support frame 
5. In each case the winch wires extend further from the support frame 
through wire guides 6b on the rings in the foldable rescue stocking 7, 
through wire guides 6a in the bottom of the reception raft and on to 
termination points in the bottom frame 1. The bottom frame 1 can be 
lowered into the water and have a more or less stabilizing effect on the 
stocking and reception raft depending on the weight, design and depth in 
the water. In order to prevent the bottom frame 1 from moving sideways in 
the water due to current resistance during the heaving movements of the 
boat, the bottom frame can either be a heavily perforated, streamlined, 
open grid construction or designed as a compact weight. The tension in the 
wires 4 can also be stabilized by giving the winch 8 a known per se 
constant tension function. For example, the winch 8 which supports the 
bottom frame 1 can be of a type which absorbs a minimum tension in the 
support wires if the support frame and bottom frame are moved relative to 
each other during operation. The packed life rafts 3 can rest on 
projecting arms on the bottom frame 1 as illustrated in FIG. 4 and FIG. 5, 
or they can be suspended from hooks or straps under the bottom frame as in 
FIG. 7. 
In both cases the life rafts 3 are deployed in such a way that they are 
released from the bottom frame 1 by their own buoyancy when the bottom 
frame is lowered into the water by means of the winch 8, while 
simultaneously the stocking 7 is unfolded and the reception raft 2 
inflated. The life rafts 3, however, will still be detachably connected 
with the reception raft 2 by means of a mooring rope 24 and possibly also 
release cords 25. The reception raft 2 is kept in position laterally by 
the wires 4, but is permitted to follow the vertical wave movements 
independently of the vertical movements of the bottom frame and support 
frame, thanks to the vertical freedom of movement of the wire guides 6a, 
6b. The invention does not comprise any special new features in the actual 
rescue stocking, which can in principle be of any known type. In the 
preferred illustrated embodiment, which is protected by, amongst others, 
NO patent 149760, the length of the escape stocking 7 is automatically 
adapted to suit the distance between the support frame 5 and the reception 
raft 2, while at the same time the stocking is constantly extended 
approximately in a vertical position and very little affected by wind, by 
means of the wires 4 and the wire guides 6b. In this example, the escape 
stocking 7 is partially unfolded or folded from below according to 
requirements, in the bottom of the reception raft 2. 
In relation to previously known evacuation systems for ships, the invention 
according to the principle claim offers the following advantages amongst 
others: 
Even during the actual lowering of the escape stocking 7 not only is the 
reception raft 2 included, but also a set of life rafts 3, thus 
immediately establishing a complete escape route away from the ship. 
The evacuees are not exposed to risk in the critical lowering phase for 
raft, lifeboat or equipment. 
The evacuation means is continuously available once it is lowered into an 
operative position. 
The device is normally stowed in a position protected from the effects of 
wind and weather with the result that the system requires little 
maintenance and will be highly accessible. 
The winch wires 4 in the wire guides 6a, 6b and the weight of the bottom 
frame 1 stabilize the stocking 7 and the reception raft 2 in an operative 
position against wind and sea forces. 
The rescue system is supplied as a complete and compact unit, which in 
itself is sufficient to initiate evacuation independently of any separate 
raft systems or the like. 
The entire system can be operated with a very few simple movements, and a 
minimum of demands are made on the operator's competence. 
Embodiments for which protection is sought by dependent claims comport in 
various combinations the following possible extra advantages: 
The system can be built into the ship's side behind a hatch 9 which is 
opened at the same time as the support frame 5 is pushed out into an 
operative position. This means that evacuees avoid the necessity of going 
out on to an open deck before evacuation can start. It also means that the 
ship's external design can be more freely formulated. 
Evacuation can take place directly from the restaurant or restaurant deck. 
FIG. 2 shows an embodiment in which lifebelts 13 and warm clothing 14 are 
available in a fire-protected room 12 with preferably direct access from 
one of the ship's most frequented rooms such as a dance restaurant. 
Descent in the escape stocking can be carried out directly from this room, 
preferably according to instructions from audiovisual aids 15. 
The system can be designed in such a manner that the force of gravity alone 
can move the support frame 5 from a parked to an operative position by 
means of an extrusion mechanism 16 when a locking mechanism 11 is 
released, see FIGS. 6 and 6A. The extrusion mechanism 16 can be designed 
in several ways, e.g. by means of a hinged mounting of the support frame 
under the lower rear edge, by having the support frame move on rollers in 
tracks for this purpose, or by means of another mechanism design which in 
the course of the movement from parked to operative position never passes 
a position where the device's centre of gravity is located higher than or 
as high as in a parked position. However, the possibility of 
gravity-operated extrusion mechanisms 16 is not a limiting factor for the 
extent of protection, since the mechanism according to the main claim can 
also include hydraulic cylinders 19, 26 or other powered extrusion 
mechanisms. 
All the vital functions of the system, including extrusion of the support 
frame 5 and subsequent lowering of the bottom frame 1 with reception raft 
2, stocking 7 and rafts 3, can be remotely controlled from the bridge. 
This can, e.g., also be easily extended to include opening of door locks 
to the evacuation room 12 and starting of the instruction video 15 
together with the obvious activation of alarms etc. Even though facilities 
of this nature cannot replace the need for human contact and individual 
help from the crew, it can free the crew to take care of all those who 
cannot manage on their own with the help of such pre-programmed 
instructions and aids. This kind of possibility for remote control from 
the bridge is also an advantage in view of the fact that it is always the 
captain on the bridge who has the responsibility for the passengers and 
crew and who gives orders as to when evacuation should begin and which 
evacuation means should be used. However, the device does not necessarily 
have to be operated from the bridge. On the contrary it will clearly be 
advantageous in view of the risk of interruptions in power, hydraulic or 
communication networks in a crisis situation that the device can be easily 
operated locally if the situation so demands. 
On account of the risk of a "dead ship" (failure of the power supply), it 
is also desirable that the winch 8 which is used during lowering of the 
bottom frame with rafts and escape stocking can be operated without an 
external power supply. This can be solved in several known per se ways, 
e.g. by providing the winch with an independent diesel-operated power or 
hydraulic set, by using a hydraulic accumulator 20 or an electrical 
accumulator, or by providing the winch with a hydraulic or mechanical 
brake, e.g. a centrifugal brake, which gives a controlled lowering speed 
with gravity as the motive power. The latter is sufficient for deployment 
in the case of the embodiment according to FIGS. 1-6, where the force of 
gravity supplies all the power necessary for deploying the rescue system 
to the ready-for-use position which is illustrated in FIG. 1. 
In those embodiments where deployment is implemented by means of the force 
of gravity, a simple blocking mechanism is necessary to keep the system 
packed when it is not in use. An example of such a simple blocking 
mechanism 11 is illustrated in FIG. 6. Here the locking arm 21 engages 
with a cut-out 24 on the support frame 5. The locking arm 21 can be 
actuated manually when the padlock 23 is removed, or it can be actuated by 
the one-way cylinder 22 which can be remotely controlled from the bridge, 
and which if necessary can be supplied with sufficient force to break the 
padlock 23. The key to the padlock 23 can be carried by all the crew 
members, or it can be placed behind a breakable glass in an alarm 
activator. 
If a winch drum is used with brake but without a permanent motor, the drum 
shaft can be equipped with splines or similar means suitable for a 
portable air motor or the like, thus enabling the system to be pulled up 
again after an exercise. A simple hydraulic pump can also be used on the 
drum shaft, which acts as a brake when the fluid flow in a locally closed 
circuit is choked. This local system can obtain its oil from a small tank 
located at a greater height, while at the same time there can be a 
connection point for external supply of hydraulic oil under pressure from 
a portable unit, if the pump is to be used as a motor for pulling the 
system up again.