Detachable connector for the transmission of drive energy to submersible pile drivers, cut-off equipment or similar work units

In order to transmit drive power to piling and cut-off devices (21) or the like usable under water from above the surface of the water to the underwater working device (21), long, heavy and expensive umbilical lines (27,20) with incorporated electric power leads or bunches of long, parallel hydraulic pipes are used which are permanently secured to the working device (21) and must therefore be handled in synchronism therewith, which is not always successful and can lead to damage. The proposal of the invention makes it possible to handle all the umbilical lines (20) and leads (23) including any power transmission means (25) incorporated therein separately from the working device (21) and to have a releasable plug connector (24, 26) at their lower end for direct or indirect connection to the working device (21). This avoids the risk of damage. The connection can be made at any time even outboard and under water.

BACKGROUND OF THE INVENTION 
This invention deals with a detachable connector for the transmission of 
drive energy to submersible pile drivers and cut-off equipment or similar 
equipment from above the water surface to the submerged work units. 
For underwater pile driving on the sea floor, the pressure medium required 
for driving the equipment is supplied through a pressure medium circuit 
with long hoses from above the water surface to the work unit. Because of 
the flow resistance in the hoses, this is only feasible up to a certain 
water depth. Either the hose diameter must be increased or several hoses 
must be utilized next to each other, so that the flow resistance can be 
kept low and the pressure medium pumps can still cope with the additional 
pressure required to overcome it. Finally, the limits of feasibility, 
economy and also handling are reached. 
In that case, a submersible drive unit is connected with the equipment and 
lowered together with it, supplying pressure medium through a short closed 
circuit, while, for the operation of the drive unit, electric energy is 
supplied by means of a long electric power cable from above the water 
surface with now much lower resistance, i. e. energy losses. For the 
operation of this kind of work unit/drive unit combination, at least one 
line for the supply of compressed air to the work unit is usually required 
in order to compensate for the outer pressure on enclosed empty spaces, 
and control lines for the control and monitoring of the work unit are also 
needed. 
All these lines are gathered in one conduit only, the umbilical, so that 
only one line need be handled. 
The umbilical is heavily reinforced for protection of the internal lines 
and for loading with tensile forces. It makes the greatest demands on 
manufacturing and can cost up to US $1400.00 per meter. It is 
substantially more expensive than a lightweight umbilical, as used for the 
operation with long hoses described in the beginning, which contains only 
control lines but no electric power cables. Depending on the equipment 
size, the energy to be transmitted and the operating depth, a long 
umbilical with accessories can therefore be more expensive than the pile 
driver itself. Price and fear of damage discourage its use. 
Therefore, again and again, solutions have been tried using even longer and 
an even greater number of parallel hoses and lighter umbilicals; although 
these solutions appeared cheaper, failures have been more frequent because 
of high risk handling and ensuing higher costs. This is because the cost 
of one hour of downtime of a support ship can be as high as US $17,000.00, 
not counting the water pollution caused by the hose failure. 
The costs for the heavy umbilical with winch, as well as for the pile 
driver/drive unit combination are driven even higher, because, in 
anticipation of failure of lines in the umbilical and/or one or more 
motor-pump units, the umbilical is equipped with a greater number of 
electric power cables and signal lines, or the drive unit is equipped with 
a greater number of, or larger, motor-pump units than required, since a 
quick remedy is currently not possible in the eventuality of a failure. 
Moreover, the working speed of the equipment is based on standards which 
are common to conventional pile driving above water, which drives up the 
capacity of the work unit unnecessarily causing additional costs which are 
not commensurate with the derived benefit for underwater work. 
The present situation of incurred downtime and damage costs of several 
million dollars has been tolerated for years. This is technically and 
economically unsatisfactory and this is also unsatisfactory because the 
expensive underwater equipment is needed only infrequently and only for 
short periods of time, i. e. it cannot be amortized quickly enough. 
However, the operation with long hoses in the appropriate applications is 
also still unsatisfactory and in need of improvement. 
Similar problems occur with other work units, especially with underwater 
cut-off equipment which will be utilized more and more in future under 
similar conditions in the removal of drilling platforms. 
SUMMARY OF THE INVENTION 
The object of this invention is to provide a detachable connector for the 
transmission of energy to equipment of the aforementioned kind, which 
makes it possible, at lower equipment cost, to transmit drive energy more 
reliably and economically, to improve the ability to replace components 
and to utilize them more diversely. Therefore, its deployment is made more 
economical. 
The means for attaining this object is for detachably transmitting 
electrical hydraulic energy from a drive unit to a submerged work unit. 
The drive unit is connected to a support ship, and the detachable 
underwater connector includes an underwater socket part and an underwater 
plug part. The underwater socket part attaches to a submerged underwater 
work unit having a wet connectable electric plug capable of transmitting 
electrical signals to the submerged work unit. The underwater socket part 
also has a pair of pressure medium channels in communication with a 
corresponding pair of pressure medium channels in the submerged work unit 
for transmitting hydraulic energy. The underwater plug part is connected 
to the drive unit and has a wet-connectable electrical socket capable of 
receiving one end of at least one electrical cable for the transmission of 
electrical signals. The other end of the electrical cable is connected to 
an electrical signal source on a support ship. The underwater plug part 
also has a pair of pressure medium channels in communication with a 
corresponding pair of pressure medium channels in the drive unit. The 
wet-connectable electric socket is capable of receiving the 
wet-connectable electric plug to transmit electrical signals from the 
support ship to the underwater work unit, and the pressure medium channels 
are capable of communicating hydraulic energy from the drive unit to the 
underwater work unit, when the underwater socket part is detachably 
coupled to the underwater plug part according to the invention. 
This detachable connector makes it possible to circumvent the risks of 
damage during the handling of the work units by excluding from such 
handling those components which are required for the transmission of drive 
energy and deal with them separately. They can be connected with and 
detached from the work unit at any time, also outboard and underwater. 
This enables the design of lighter underwater drive units, quick 
inspection and repair, and quick interchange with cheaper components. 
These advantages derive from the fact that the work unit can remain 
outboard and only energy transmitting means (umbilicals etc.) are taken 
aboard, with or without drive unit, or are separately hoisted up full 
speed, inspected and lowered again. The state of the art is such that 
these components can practically not be separated from the work unit 
outboard or at the work site. They have to be disassembled onboard. As a 
whole unit they can be hoisted up only slowly and lowered again especially 
slowly, if they have to be pressurized with air to compensate for the 
external water pressure. 
Instead of an expensive umbilical one can also utilize a simple cable for 
the transmission of drive energy, depending on the method of operation, 
because handling is simpler and gentler. This simpler cable can be 
designed as a cheap lightweight umbilical without compressed air lines and 
without special reinforcement, but with integrated control cables, 
provided one does not choose a separate thin control cable or the signals 
are transmitted in another way. 
On the other hand, for lower power requirements, one can also utilize a 
lightly reinforced cable or lightweight umbilical simultaneously as a 
lifting element to correspond with the smaller and lighter drive units. 
Based on the improved ability to replace components, availability of excess 
power and capacity for standby purposes need not be considered in the 
equipment layout. Economical designs are possible. In the case of the 
drive unit, several electric-motor-pump-units can be combined into fewer 
or one single larger unit with lower total, yet appropriate power output, 
which is favorable from the points of view of construction, weight and 
handling. 
The interconnection of components transmitting drive energy as electricity 
or pressure medium is achieved by wet connectable parts, possibly exposed 
to high water pressure, preferably by means of multi-channel single 
plug-type connectors. Before the operation begins, they are secured 
against pull-out and torque exerted by the electric motors either 
automatically by means of pressure medium or by other outside means. 
The proposed solutions also improve the operation with long hoses from 
above the water surface. It is also possible to change over already 
existing underwater work units and installations partly or completely, as 
proposed. 
The detachable connector according to the invention is economically usable 
up to practically unlimited water depth, and can be used with pile 
drivers, vibration-, cut-off equipment and other underwater work units. 
Further variations of this detachable connector is described in the claims. 
Preferred application examples of the installation are described below in 
the corresponding drawings.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 shows a pile driver 1 free standing on top of the foundation pile 2 
connected with the support ship 3 in the coventional manner. The pile 
driver 1 is lifted and lowered by the crane 9, boom 10, and lifting rope 
11 together with the drive unit 22, which is connected by the additional 
lifting rope 12 with the pile driver 1. The umbilical 18, which connects 
support ship 3 by way of winch 13 and deviating roller 14 with the drive 
unit 22 for the supply of energy and compressed air or signals, must be 
moved in unison during all operations. Inevitably the same applies to the 
lines 23 which firmly interconnect pile driver 1 and work unit 22, and 
which are endangered together with the expensive umbilical 18. 
The endangering is minimized by an umbilical 20 supported by a winch 15, 
and extending to the drive unit 22 where it can be plugged in and 
unplugged at any time, because the electric power cable and control line 
plug connection 24 (similar to FIG. 13) is made only after the endangering 
action, but at the latest underwater when the pile driver 1 is already set 
on the foundation pile 2. In addition, the umbilical 20 is cheaper because 
it contains only electric power cables and control lines. In addition to 
the lifting rope 11, instead of the umbilical 18, only the compressed air 
line 16, which is replaceable at little cost, continues to be connected 
with the drive unit 22, and from there with the pile driver 1, because 
compressed air supply is required from the beginning of the dive. This 
gentler handling even makes it possible to install a still more favorable 
electric power line 20a and a separate control line instead of the 
umbilical 20. 
The number of plug connections 24 depends on their transmission capacity 
and the energy requirement. The plug connections are made with the robot 
tool 8 of the remote controlled underwater vehicle 6 which is connected 
with the support ship 3 by means of line 5. 
The vibration pile driver 21 shown in FIG. 2 is connected, in contrast to 
FIG. 1, with a smaller, simplified and separate drive unit 25. As in FIG. 
1, the energy supply of the vibration pile driver 21 is provided from the 
support ship 3 by way of the component winch train 13, deviating roller 
14, umbilical 20, electric power line and control line plug connection 24, 
drive unit 25 and supply line 23, which is detachably connected with 
vibration pile driver 21 by means of the pressure medium and control line 
plug connection 26. 
The supply line 23 and the drive unit 25 with umbilical 20, that is the 
whole train of energy transmitting components, can therefore be handled 
singly and gently according to its requirements. 
Now the drive unit 25 no longer acts as a load carrying element between 
lifting ropes 11 and 12, as shown in FIG. 1. The lifting rope 12 is 
therefore not required. The drive unit 25 can have a lighter weight design 
because it is not required to carry load. It can now also be suspended 
from an appropriate tension carrying umbilical 20, thereby eliminating the 
lifting rope 27. 
The plugging in operations are carried out with the help of underwater 
vehicle 6. 
In FIG. 3, the pile driver 1 is powered by a directly mounted, conventional 
drive unit 17 by way of a small internal closed pressure medium circuit 
(not shown). 
The energy supply is optimized, similar to FIG. 1, in that the expensive 
umbilical 18 is divided up into the compressed air line 16 and the lifting 
rope 11 carrying the pile driver 1/drive unit 17 combination, with both 
lines being handled simultaneously, and the umbilical 20, handled 
separately, now still carrying only electric power and control lines which 
are detachably connected to the drive unit 17 by means of the plug 
connection 24. 
Apart from the cost savings derived from dividing up the umbilical 18 and 
its lowered risk of damage, the advantage of its improved interchange 
possibility remains, as in FIG. 1. 
In FIG. 4, a smaller, simplified drive unit 25 is directly connected with 
pile driver 1. In contrast to the variation shown in FIG. 3, the drive 
unit 25 is connected as a whole with the pile driver 1 by means of a 
detachable pressure medium and control line plug connection 26 (see 
explanations for FIG. 12 and 15). The unplugging of plug connection 26 is 
affected by pulling with the lifting rope 27 or with the umbilical 20 or 
cable 20a. As required one or several drive units 25 can be arranged 
around the pile driver and connected with it. An imbalance is compensated 
for by a counterweight 28. 
In FIG. 5, the drive unit 25 is connected, in contrast to FIG. 4, directly 
and coaxially to the upper portion of the pile driver 1. This is why two 
ropes 29 are utilized which are connected at their lower ends to the sides 
of the upper portion of pile driver 1, and at their upper ends to the 
lifting rope 11, without contacting the drive unit. Compressed air is 
supplied by means of line 16. The drive unit 25 is connected with a 
detachable plug connection 26, as described in FIG. 4. It is supported on 
the pile driver by means of a spring 30 which cushions shocks. This 
arrangement is favorable for symmetry reasons. 
FIG. 6 shows a pile driver 1 which is connected with the support ship 3 by 
means of long pressure medium lines 23 next to a control line 4, by way of 
the deviating roller 14 and the winch 13. The pile driver 1 is connected 
with the support ship 3 for the supply of compressed air by means of line 
16 by way of the winch 15, and for lifting and lowering by means of 
lifting ropes 11 and 29. 
For connecting lines 23 with the pile driver 1, a detachable pressure 
medium and control line plug connection 26 with distributor piece 31 is 
provided. The desired gentle handling is provided by the possibility of 
separating the lines 23 and the control cable 4 from the pile driver 1. 
In FIG. 7 are shown, as a side view of FIG. 6, several parallel pressure 
medium lines 23 and a control line 4 in the center, all of which terminate 
at the distributor piece 31. This line/cable bundle is directly connected 
with the support ship 3 or with an intermediate underwater drive unit. The 
large number of hoses 23 with small diameter are used in order to avoid 
using a very expensive type of hose with corresponding large diameter for 
the feed and return lines. As an alternative, standard hoses in 
commercially available short lengths are coupled together. But since the 
latter do not measure up to the rough handling and since the many 
couplings often leak, trouble arises, and frequently in the vicinity of 
the pile driver. To remedy this difficulty, the pile driver 1, together 
with the firmly affixed hoses, has to be lifted up in order to exchange 
the damaged hose piece outboard, or the pile driver has to be lifted 
onboard and laid down on deck. 
According to the invention the repair of such damage is simpler and 
achieved with greater certainty, because the lightweight hose bundle can 
be separated at the plug connection 26 and lifted up separately by means 
of the lifting ropes 32 at any time, while the work unit remains 
underwater or outboard. See FIGS. 8 and 9. 
FIG. 8 shows a pile driver 1 held outboard in a fixture 33. The lines are 
connected or disconnected during the short period of time at the ship's 
side after the pile driver has been lifted from the deck and swung 
outboard, or after it has been lifted up from below. The latter is 
important if the plug connection is equipped with a lock which has to be 
actuated by remote control from an underwater vehicle, and if the vehicle 
is defective, so that the separation cannot be affected underwater. This 
is done here so that the sensitive parts can be separated before the 
dangerous placement on deck. 
The arrangement shown in FIG. 9 corresponds to that of FIG. 8 except that 
here the lines 4 and 23, feeding directly from the winch 13 or 
alternatively by way of the deviating roller 14, are connected to the side 
of the freely and outboardly hanging pile driver 1 which is easily 
accessible from the ship's side in order to make use of the invention's 
advantages. 
Corresponding with the diverse application possibilities, FIG. 10 shows 
underwater cut-off equipment 50 which is placed on top of a driven 
foundation pipe pile 51 and whose shaft 52 with the cut-off tool 53 
protrudes into it, so that it can be cut off below the sea floor in 
section C. The cut-off equipment 50 is driven by an underwater drive unit, 
which is powered electrically or hydraulically from above the water 
surface. It is supplied conventionally, depending on type of drive, either 
by means of an umbilical or long pressure medium lines 23 including 
control line. 
In both cases, according to the invention the cut-off equipment 50 is first 
handled without energy supply lines. They are connected later. Since 
cut-off equipment consumes very little power, equipment needed for 
observation such as an underwater vehicle 6 with television camera 
including lifting equipment can be utilized at low cost. Thus, electric 
energy for the electric-hydraulic drive unit on the cut-off equipment 50 
and signals are preferably supplied to the cut-off equipment 50 by means 
of the umbilical 5, the launch cage 19 for the underwater vehicle 6 and 
one or two connection lines 7 connected by means of an electric plug 
connection 24. 
If long pressure medium lines 23 supply the drive energy from the support 
ship 3 to the cut-off equipment 50, then these follow the same supply 
path. They terminate in a pressure medium and control line plug connection 
26 at the cut-off equipment 50. 
Furthermore the cut-off equipment 50 is connected with the support ship 3 
by means of the lifting line 11 and the supply line 16 for compressed air 
or cutting medium. 
In addition to the advantages explained above, there are those of utilizing 
existing components. 
FIG. 11 shows a lightweight drive unit 25. It consists of an underwater 
electric motor 34, a pressure medium pump 35 and a pressure medium tank 
37. These modular components are joined together by means of a coupling 
piece 38 to establish a drive unit. The electric motor 34 is connected 
with its pedestal 39 to the upper part, the pressure medium pump 35 with 
its flange 40 to the lower end and the pressure medium tank 37 at the 
flange 41 of coupling piece 38. The flange 41 is shimmed with a slightly 
elastic and flexible material in order to dampen shocks to the electric 
motor 34 and to bridge machining tolerances between connecting surfaces 
for lines 12 and 13 when, instead of these, couplings with machined 
surfaces are used to ensure leak tight connections. See FIGS. 12, 14, 15 
and 17. 
A valve block 36 is attached to the pressure medium pump for the required 
operating controls. Pressure medium flows from the flexible connection 42 
through valve block 36 to pressure medium pump 35 and then flows 
pressureless in short circuit loop either completely or partially back to 
the pressure medium tank 37 through flexible connection 43, or flows 
either completely or partially through connection 44 to the work unit and 
back to pressure medium tank through connection 45. A pressure 
equalization cylinder 46 with floating piston 47 communicates through 
openings 48 with the external water on the one side and with the pressure 
medium on the other. It ensures pressure is equalized between external 
water and pressure medium tank. 
The energy is supplied by means of the umbilical 20 which is, because of 
the lightweight drive unit 25, simultaneously the lifting element. The 
control line 49, exiting from the umbilical 20 or coming separately from 
above, continues to the work unit. 
By way of dashed lines it is shown how two drive units may be joined in a 
simple manner. 
In FIG. 12, the drive unit 25 is directly and coaxially connected to the 
top of the work unit (1, 21 or 50) by means of a pressure medium and 
control line plug connection 26. 
The plug connection 26 consists of the plug part 54 which is fastened to 
the drive unit and the socket part 55. The plug part contains pressure 
medium channels 56 and 57 which continue on in socket part 55 and 
terminate in hose connection 58 and 59 which feed pressure medium into and 
return the same from the work unit. The channels have check valves 60 
which prevent oil from leaking out and water from entering into the 
systems when unplugged. 
The control lines 49 are connected in the plug part 54 to a coaxial, 
wet-connectable electric socket 61, whose plug 62 is located in socket 
part 55, and which connects control lines 49 with the work unit. The 
support of socket 61 is preferably elastically displaceable in the 
transverse direction in order to avoid problems caused by off-centering of 
the connecting parts 54 and 55. 
The electric plug connection 61/62 is made simultaneously with the pressure 
medium connection 54/55. For work units 1, 21, which are subject to 
vibrations, the socket part 55 may be mounted in a flange ring 63 and 
spring loaded with a spring 30. The plug connection is plugged in by the 
weight of the drive unit. As spaces 64, 65 become smaller during plugging 
in, or fluctuate in size because of spring action, the displaced water 
escapes through openings 66 and 67. 
In order to avoid damage to the sealing surface on plug part 54, a 
protective skirt 69 is provided which has a large guide cone 68 on its 
lower end facilitating plugging parts 54 and 55 together. 
The lifting element is the umbilical 20 itself which is protected against 
excessive bending by a bending resistant sleeve 70. It must be capable of 
unplugging plug part 54 by overcoming the small forces due to retentive 
connections. Otherwise a lifting rope will be used. 
FIG. 13 shows an embodiment according to FIG. 12, where the electric socket 
part 61 with plug 62 for control cable 49 is relocated to the outside and 
is connected to the work unit 1, 21, 50 by means of line 95, thereby 
simplifying the interior of plug connection 26. Since parts 61 and 62 are 
connected to spring loaded socket part 55, they are also spring loaded. 
The coaxial cylindrical pin of plug part 62 has as many ring contacts 96 as 
there are signals to be transmitted, provided there are no facilities for 
information processing and transmission on work unit 1, 21, 50 that allow 
several different signals to be transmitted through a single ring contact 
96. 
If control line 49 contains a compressed air line, then compressed air can 
be transmitted through the hollow plug part 62 and a correspondingly 
designed socket 61 to the work unit. In this case check valves 60 are to 
be provided in both parts as described in FIG. 12. 
Plug 62 is plugged in by the underwater vehicle 6, as explained under FIG. 
2, and unplugged together with the drive unit 25 during unplugging of plug 
connection 26 by pulling on the umbilical. If required, the plug 
connection parts 61/62 can be locked together, e.g. similar to FIG. 15 and 
FIG. 16. 
In FIG. 14 two interconnected drive units 25 are connected to the top of 
the work unit (1, 21, 50) by means of a distributor piece 31 and the 
pressure medium and control line plug connection 26. The distributor piece 
combines pressure medium coming from the pressure medium pumps of drive 
units 25 in channels 71 and 72 into channel 73 and feeds it through 
channel 56 and through plug connection 26 to the work unit (1, 21, 50). 
Pressure medium coming from the latter through channel 57 to channel 74 
and distributed to channels 75 and 76 is returned to the pressure medium 
tanks of the two drive units 25. 
FIG. 15 shows, in contrast to FIG. 12, a pressure medium and control line 
plug connection 26a with a locking device 77 which simultaneously serves 
as a pulling device assisting in securely plugging the two parts together. 
The parts 54a to 69a of plug connection 26a correspond functionally with 
those of plug connection 26 of FIG. 12. They are therefore not described 
again here. 
The plug connection 26a is shown just before the plugging in operation. The 
socket part 55a is already engaging the guide cone 68a of plug part 54a 
and the locking hook 78 is about to swivel and hook on below shoulder 81 
as piston rod 79 of cylinder 80 is retracted. As piston rod is retracted 
further, parts 54a and 55a, and simultaneously electric socket parts 61a 
and 62a, are pulled together by the pulling action of the locking hook 
which rides in guide 88, and which finally firmly tensions them together 
unless the weight of the drive unit 1 is sufficient to effect this by 
itself. Since the contact areas are pressed together, any torque created 
during starting and running of the electric motor is absorbed by friction 
in the contact areas. 
The locking mechanism 77 is actuated by control valve 81 whose control rod 
82 is manipulated underwater by underwater vehicle 6 or other suitable 
means. In order to retract piston rod 79, pressure medium is sent from the 
high pressure accumulator 84 to the lower chamber of cylinder 80 through 
line 83, while simultaneously the displaced hydraulic fluid from the upper 
chamber of cylinder 80 is sent through line 85 to the low pressure 
accumulator 86. 
Unlocking occurs through a spring (not shown), which is located, e.g. in 
the upper chamber of cylinder 80, and which pushes the piston rod in the 
initial position; simultaneously lines 83 and 85 are connected with the 
low pressure accumulator 86 transfering the required pressure medium. 
If there is insufficient pressure medium in accumulators 84 and 86, i.e. if 
pressure falls below the lower threshold, it is replenished through check 
valves 87 from the closed pressure medium circuit. Conversely, an excess 
of pressure medium is released from the accumulator 84 or 86 to the 
pressure medium circuit through pressure relief valves (not shown). 
The check valves 87 are placed in the closed pressure medium circuit of the 
work unit (1, 21, 50), as functionally required: For the high pressure 
accumulator 84 in pressure channel 56a, and for the low pressure 
accumulator 86 in return channel 57a. 
The drive energy is supplied by means of the umbilical 20 or separate 
electric power cables and control lines. 
If required, a spring 30 as shown in FIG. 12 can be included in this plug 
connection also. FIG. 16 shows a partial view of plug connection 26a with 
locking hooks 78 of which there are three distributed on the circumference 
to ensure uniform pull and clamping force, and also friction force to 
counteract torque created during starting and running of the underwater 
electric motors. 
The three drive units shown in FIG. 17, interconnected to produce greater 
drive energy, are detachably connected with the work unit 1, 21, 50 by 
means of a distributor piece 31, as explained for FIG. 14, pressure medium 
lines 44 and 45, control line 49 and plug connection 26a. The pressure 
medium lines 44 and 45 supply and return, respectively, pressure medium to 
and from work unit 1, 21, 50 by means of channels 56a, 58a and 57a, 59a, 
respectively. 
Electrical energy is supplied by the umbilical 20 to the electric power and 
control line plug connection 24, from where it is distributed to the 
electric motor of each drive unit 25 by means of lines 89. The control 
line 49 also branches off from the plug connection 24. 
The drive units 25 with plug connection 26a are raised and lowered by 
lifting ropes 32 and 27 and, after unplugging plug connection 26a, can be 
handled as one single assembly, separately from the work unit 1, 21, 50. 
The advantages of this configuration correspond to those described above in 
reference to FIGS. 2, 7 and 8. 
FIG. 18 shows how channels 92 and 91 are arranged in distributor piece 31, 
collecting pressure medium from drive units 25 and conveying it to 
connection 44, or distributing returning pressure medium from connection 
45 to drive units 25. Also, channels 91, by virtue of interconnecting and 
connecting with pressure medium tanks 37 of drive units 25, ensure that 
pressure medium tanks are communicating pressure medium with each other. 
Additionally, each individual drive unit 25 is connected to the distributor 
piece 31. It firmly connects them to each other to establish a single load 
bearing construction unit. If extended outwardly, it can also serve as the 
base for the protective skirt 93 indicated by dashed lines. 
The distributor piece 31 contributes significantly to the desired light 
weight and economic design of the detachable connector. 
In contrast to FIGS. 13 and 16 where the drive units 25 are directly 
connected with distributor piece 31, FIG. 19 shows in more detail an 
application according to FIGS. 6 and 7 where a plurality of pressure 
medium lines 23 are connected with channels 44 and 45 which continue on 
through plug connection 26a to work unit 1, 21, 50 by way of connections 
58a and 59a. 
The compressed air line 16 is separate, unless the plug connection 26a is 
to be plugged in or unplugged outboard but not underwater. In this case 
the compressed air line 16 is connected as shown and additional channels 
(not shown) are provided inside the plug connection 26a. 
The distributor piece 31 can, of course, also be arranged at the upper end 
of lines 4 and 23, in order to provide an interface for equipment 
components suitable for the particular operation at hand. The advantages 
of this application are already described above in reference to FIGS. 6 
and 7. 
FIG. 20 shows a centrally connected lifting rope 11 and distributor piece 
31/plug connection 26a combination connected on the side of work unit 1, 
21, 50 as in FIG. 9, and the distributor piece 31 in connection with lines 
16, 23 and 49 according to FIG. 19. The lines and lifting ropes 32 are 
laid down on a device 95 which safeguards against excessive bending and 
which is affixed to distributor piece 31. 
An alternative possibility for affixing the parts combination is shown by 
way of dashed lines. 
The advantages according to this invention can be favorably applied to the 
present diverse deployment practice of underwater work units. They shall 
be useful for the already anticipated deployment of similar equipment.