Non-Subscriber Extract
Surviving SUBSUNK
Surviving SUBSUNK
Submarine
rescue technology has been thrust into the limelight in the wake of the
Kursk tragedy. Philip Sen looks at the problems confronting submarine
rescue services, and examines current and projected capabilities within
NATO.
It is every
submariner's worst nightmare. Systems failure, a weapon handling error
or collision has left the submarine and its crew trapped beneath the waves.
As supplies run out and the air turns foul, there may be only one thing
keeping the men alive - hope of rescue. Yet the logistical problems of
evacuating a sunken submarine (an alert triggered by the NATO reporting
signal SUBSUNK) are varied, requiring meticulous planning and co-ordination.
A stark illustration of this is the fact that there has been only one
successful submarine rescue in history (USS Squalus in 1939). Since the
Second World War, 615 have died in submarine accidents, 118 of those in
perhaps the most public naval tragedy of recent times, the loss of the
Russian 'Oscar II'-class boat Kursk in August last year. And as recently
as December a Brazilian submarine sank alongside, fortunately without
loss of life.
Escaping from a Distressed Submarine (DISSUB) without outside assistance
is not unknown, but is fraught with hazards. The maximum depth for a controlled
free ascent from a DISSUB is just 180m, and notwithstanding the risks
of embolisms and 'The Bends' (caused by nitrogen absorbtion into the bloodstream)
conditions outside the vessel are an unknown risk. Hypothermia was one
of the killers during the Komsomolets disaster in 1989, and in 1959 several
escapees from HMS Truculent died after being washed away by estuary tides.
Overall, the consensus among the submarine community is that in most scenarios,
the safest option is to await rescue.
"Any country in the world that has a submarine problem can ask NATO
for help," says Captain "Bill" Hanson, Chief of Staff for
Submarines East Atlantic and Allied Forces North. "Everything NATO
has can be called upon to make up a 'menu' of assets available. Furthermore,
the Swedes approached NATO to help during the Kursk incident, and other
countries would offer their assets in the same way." Preformatted
messages such as NATO ATP-10 publications and the ATP-57 technical manual
(recently ratified as MTP-57) aid commanders of different nationalities
in co-ordinating a rescue effort involving myriad assets being put together
at short notice. The scenario detailed below assumes the UK Submarine
Rescue Service is answering the call with the LR5, but procedures are
broadly similar for any rescue effort.
The Commander Submarines (COM-SUB) will have established a "moving
haven", a box based on the last known communication from the DISSUB
which tells search assets where it is likely to be located. Maritime patrol
aircraft and surface ships within range will be called out, and with luck
the DISSUB's flares, smoke, buoys or transmitter capsules from submerged
signal ejectors will be detected. If technology proves ineffective, at
predetermined intervals the rescuers will switch off sonar equipment and
conduct a listening watch for survivors banging on the sides.
At
the same time, the complexities of deploying rescue equipment to the scene
must be addressed. Though it is likely military air transports, such as
the C-130 Hercules, C-5 Galaxy or C-17 Globemaster will be employed whenavailable,
a key consideration is finding a suitable landing strip or runway close
to the most suitable port. Former Warsaw Pact aircraft available on the
open charter market such as the Antonov An-124 are also coming into favour
for this part of the operation.
Commercially chartered road transport may be required to move rescue equipment
from the airstrip to a suitable port, where on-scene personnel will be
arranging a suitable Mother Ship (MOSHIP), whether a military warship
or a commercially chartered vessel of opportunity (VOO). For this purpose,
there is a frequently updated database derived from agreements with various
major shipowners. It is designed to help rescue commanders find VOOs with
adequate accommodation, deck space, strength and manoeuvrability; ideally
dynamic positioning capability is required, or at least a small bow thruster
to enable precision positioning over the DISSUB.
Taking
into account speed and distance considerations, the closest ship is not
always the optimum solution: nor, for that matter, is the closest port
of embarkation due to the cranage requirements to place at least 70 tons
of stores and rescue vehicle equipment aboard the MOSHIP. "There
will always be a different answer to the problem," says Cdr Alan
Hoskins, the current UK Submarine Escape and Rescue Project (SERP) manager,
"but availability of a mother ship is the most critical factor".
While this is going on, a Submarine Parachute Assistance Group (SPAG)
may have been dropped at the DISSUB location to provide medical assistance
for any men who have already managed to escape from the submarine. Mobilising
within six hours, SPAG personnel can also initiate communications with
the DISSUB with underwater telephones. Prior to the rescue vehicle's arrival,
nearby ships could deploy a sonar-equipped Remotely Operated Vehicle (ROV)
such as the UK Scorpio. Not only can the ROV send TV images to the rescue
team, but it can begin to clear debris, record vital data such as temperatures,
currents and radiation levels and drop tracking beacons onto the DISSUB
to aid location.
On board the MOSHIP and auxiliary vessels gather a large number of people.
Under the overall responsibility of the On-Scene Commander is the Co-ordinator
Rescue Forces (CRF), the SERP representative (who co-ordinates commercial
assets and liases between the rescue team and off-shore manager) and the
contracted or delegated MOSHIP captain, who is responsible for everything
and everyone aboard. Only when the offshore manager and MOSHIP master
are satisfied with the ship with all the additional equipment and personnel
can the CRF begin to deploy his equipment, making for a delicate command
and control balance.
There will be a naval party consisting of divers or swimmers, communications
and Integrated Navigation and Tracking Outfit (INTO) operators and administrative
staff. At least one medical party or SMERAT (Submarine Escape and Rescue
Advisory Team) may be on scene including experts in monitoring and treating
the effects of nuclear radiation. Decompression chamber operators and
assistants must also be embarked along with the 12 or so people needed
to operate a rescue vehicle (RV) and associated equipment. Therefore,
there could be 40 or more involved in the rescue. Add to this the logistical
problems of providing food, water, accommodation and emergency equipment,
plus dealing with the increasingly inevitable media attention, and the
commanders' jobs are far from easy.
Meanwhile, in the 72h or so that it takes to get equipment and personnel
on scene, the DISSUB survivors are still waiting. Cdr Paddy Ryan, former
SERP desk officer with the LR5, is convinced that this is where psychology
must be taken into account. "Communication with the DISSUB goes a
long way to keeping people alive," he says, "Good morale aids
their chances." ROVs are especially useful for "pod posting"
- delivering pods containing food, fresh water, oxygen candles, CO2 absorbers,
medical supplies, clothing, flashlights and even newspapers in order to
maintain morale aboard, and delay deterioration of the survivors' condition.
The
large number of scenarios that must be taken into account further complicates
rescue management. Before commencing, the submarine must be pinpointed
with INTO or an ROV. The RV must be lowered into the water, cables removed
by swimmers and a trim dive undertaken before it is ready for the operation,
all procedures that take up valuable time. If pressure within the submarine
is an issue, it can be alleviated using the hose-like DISSUB Depressurisation
System (DSDS). By drawing out air from the DISSUB at the correct therapeutic
rate, the DSDS buys time for the men on board, as long as the submarine
has the right fittings in accordance with Standard NATO Agreements (STANAGs).
Assuming that the RV can mate with the submarine's rescue seat (dimensions
of which are defined by a STANAG adopted worldwide) water is pumped out
of the RV's skirt, creating a vacuum, and therefore a hard seal. The pressure
between the RV and DISSUB must then be equalised, before the hatches can
be opened and transfer of survivors begin. The 50-60 minute process is
then reversed for the RV to disconnect and return to the surface, all
of this quite possibly at an angle of 60º from the horizontal.
Reality is rarely that simple, and from the point of mating with the DISSUB
the CRF's choices actually become even harder. One problem is deciding
the order of evacuation. With pressure rising aboard the DISSUB in the
event of flooding, adding to the factors of hypothermia, nitrogen saturation
and dwindling oxygen, should the priority be the injured or those with
the greatest chance of survival? With a limited amount of space aboard
the rescue vehicle, time is of the essence. It may be the case that the
fittest must be taken out first, if only to give the rescue attempt a
moral victory. "If they'd got one person out of the Kursk,"
says NATO Submarine Rescue System (NSRS) Integrated Project Team Leader
Cdr Richard Burston, "Russia would have held its head up high".
Furthermore, the CRF must choose whether to leave medical personnel aboard
the submarine, with the subsequent problem of evacuating them as well.
Such an action should increase the chances of injured men, raise morale
aboard the DISSUB and aid the senior survivor in taking considered decisions,
but the presence of extra lungs would deplete oxygen further. Furthermore,
to lose rescue personnel on such a mission would be catastrophic.
Any DISSUB survivor, whether injured or not, will not be acclimatised
to the pressure changes he will experience upon rescue, and herein lies
the most complex logistical problem of any submarine rescue operation.
Escapees from the Peruvian submarine Pacocha, which sank in 1988, were
crippled or killed by 'The Bends', though they experienced only four to
five bar of pressure. The DSDS is an effective system, but fitting it
to the DISSUB in difficult conditions is not always possible.
Should the submarine have been half flooded, a survivor will have been
at a pressure of at least two bar and will require a minimum of 20 hours
of decompression. As the submarine continues to flood, the remaining sailors
will experience even higher pressures. As a guideline, an average man
can survive pressures of up to seven bar - exceptional individuals have
been known to cope with 10 - but clearly all must be evacuated before
the pressure becomes dangerous. Therefore, if a full crew of over 100
has survived a sinking, each individual may require different decompression
times.
If it is not enough to get all of these people (plus attendants) into
decompression chambers on the MOSHIP or auxiliary vessels, a way must
be found of getting them from the rescue vehicle to decompression without
rapidly lowering them to normal pressures during a deck transfer. "How
long can someone be depressurised and then repressurised before harm occurs?
How rapidly can you decompress someone when there's more survivors to
come?" asks Cdr Burston. "It's a very difficult issue to call.
You can't plan or practice it."
This is why Transfer Under Pressure (TUP) has become a key issue among
the submarine rescue community. Sweden's dedicated MOSHIP, Belos, has
facilities to attach the rescue submersible directly to a decompressor
and though it only has capacity for 35 people, it is a capability other
nations are envious of. The LR5 has been tested in conjunction with Belos,
but the UK SERP team would like an "ad hoc" TUP system for their
equipment. Ideas have been generated, and it was recently announced that
an invitation to tender will be issued on 6 April 2001, for delivery within
one year of the contract being placed.
Current US research on accelerated decompression may also provide the
answers. It appears that more risks can be taken if survivors are prepared
to accept temporary physiological problems. The US Navy is also working
on the Submarine Rescue Diving and Recompression System (SRDRS), which
will consist of two 33-man chambers.
Standardisation and the NSRS
The capability of rescue teams to rescue personnel from the submarines
of other nations, whether NATO, Partnership for Peace or unallied countries
such as Russia, can only be augmented by further co-operation on standardising
systems. Standardisation has a broad remit: communications systems compatibility,
whether VLF radios, underwater telephones or simple banging-on-the-hull
"tap codes"; command and control message formats; standard escape
hatches, rescue vehicle skirts, ventilation points and hose arrangements
to name but a few. Operating procedures are being updated constantly,
especially after exercises such as 'Phoenix' and 'Sorbet Royal'. Even
within NATO there are still discrepancies; for example, Germany's escape
and rescue philosophy differs from other nations' and it has yet to adopt
the standard mating hatch.
One such effort to improve standardisation has been the Submarine Escape
and Rescue Working Group (SMERWG) which meets at least once a year. Participation
is growing, and the idea has been tabled of setting up a second SMERWG
for submarine-equipped Pacific navies. A team led by Denmark is currently
looking into external ventilation and depressurisation systems and another
sub-group under SACLANT is investigating the possibility of setting up
a support cell, the NATO Submarine Escape and Rescue Organization, at
a NATO or national command in order to provide dedicated worldwide information
and assistance.
From the SMERWG arose plans for a new system to replace submersibles and
rescue vessels such as the UK's LR5, US DSRV and Italian MSM1 which are
all nearing the end of their service lives. Under this catalyst, a collaborative
programme was initiated in 1987, with a pre-feasibility study conducted
in 1990-91. Under the NATO Naval Armaments Directive, Project Group 38
was formed in 1994 and the UK nominated to evaluate the study.
Though
the project group initially involved 12 nations, only five of these provided
financial backing for the feasibility study itself, which began in 1996
and involved companies including Cable and Wireless, Lockheed Martin and
DCN. Of the five nations - France, Italy, Norway, the UK and the US -
Italy decided to withdraw due to misgivings about the availability of
suitable MOSHIPs in its area of interest and the US broke away to pursue
a design based on their own specific requirements. Italy went on to develop
the SRV300 as an interim solution, while Turkey joined the project in
2000. Australia, Canada and Sweden are currently involved as observer
nations. Though the UK is acting as host nation for what has become the
NSRS project, a steering committee chaired by France has been appointed
to act as a single customer under UK Smart Procurement principles and
to oversee compliance with user requirements.
On
18 August 2000, a Memorandum of Understanding (MoU) was signed between
the four remaining nations and a competition subsequently ran for the
two-year project definition phase, producing technical specifications
for a systems requirement document. From eight bidders, the winner of
the £700,000 (US$1million) contract to identify and assess the technologies
needed to procure, operate and support NSRS was UK company W S Atkins,
backed by a team including the National Hyperbaric Centre, Hardsuits Inc
(which in turn is involved with the design of the US Remotely Operated
Rescue Vehicle), Rumic, Stolt Offshore, Kongsberg Simrad Ltd, Telelogic
(QSS), Top Express and Virtual Presence Ltd.
The key user requirements for the NSRS are as follows:
- Availability - the NSRS shall have at least 98% availability to mobilise
for effecting rescues.
- Location - it shall be capable of deployment and operation worldwide,
except for ice covered seas and ocean areas.
- Environment - it shall take sufficient account of all environmental
conditions likely to be encountered to enable successful completion of
intervention and rescue operations, if necessary during windows of opportunity.
- Evacuation - the Time to First Rescue (TTFR) shall be under 72h to DISSUB
locations within its primary area of operation.
- Rescue Numbers - the NSRS shall rescue up to 150 personnel from a DISSUB.
- Depth - maximum rescue depth no less than 600m (objective 700m).
- Rescue Pressure - it shall rescue DISSUB personnel at DISSUB internal
pressures within a range from 1 bar absolute through to 5 bar absolute
(objective 7 bar absolute).
- Angle - it shall be capable of operation at DISSUB rescue seat angles
of up to 45º from the horizontal (objective 60º).
- DISSUB Personnel - the NSRS shall be capable of operation without assistance
from DISSUB personnel.
The final key user requirement was a late addition, coming as a direct
result of the Kursk incident where any survivors would have been in no
condition to aid their own rescue.
The feasibility study loosely identifies the composition of a Submarine
Rescue Unit as including the RV itself with at-sea support facilities,
transportation, A-frames, DSDS and TUP equipment, tracking and navigation
equipment, command, control and communications, life support stores, and
an ROV for survey, debris removal and re-supply. The projected through-life
cost for the system is £120 million (US$175m), which includes design,
building management and operation for 25 years. Of this, the estimated
cost of the equipment itself is likely to be around £18 million
(US$26.3m). There are about 70 companies "on the list" for the
next stages of the NSRS project, from nations as diverse as the US and
UK to South Africa and Russia.
The option remains open for more nations to join the NSRS programme, with
the hope that with the extra support there will be the opportunity to
build two systems rather than one. In this case, one would be located
in western Scotland and the other in the eastern Mediterranean. Another
key option is whether to keep ownership and operation of the NSRS with
government or to use commercial operators under the LR5/Rumic model.
The new US submarine rescue system, the design of which is due to be frozen
later this year, plans for two RVs operating with one set of auxiliary
equipment. Trials are set for 2003. The intention of the NSRS team is
not to compete but to co-operate with the US, and the option to buy the
US design (likely to be a Remotely Operated Rescue Vehicle [RORV]) is
not being dismissed. "Ultimately, a European NSRS and a US system
should work together, with support from other countries," says Cdr
Burston. "Ideally, the strengths of two different systems will cancel
out any weaknesses... The only thing we need to do equally well is mating
with the rescue seat." However, compatibility considerations for
A-frames and recovery systems take-up points aboard MOSHIPs and decompression
facilities are also to be addressed.
Most of these questions will be answered by the end of 2001, and an MoU
for the next phase - a through-life arrangement covering design, manufacture,
support and operation - is scheduled for signing in mid-2002. A systems
requirement design should be opened for tender in March 2003 for an in-service
date of the end of 2005.
There
are two main options: a free-swimming vehicle like the LR5 or an RORV
with an umbilical cord. Each carries its own advantages and disadvantages;
an umbilical cord gives the RV far greater endurance and excellent communications
with the surface, but restricts its range and capability in strong currents
during the rescue. Airlifting and fitting the control cabin and umbilical
cord drum to a MOSHIP could also prove problematic. A consideration with
a free-swimming design is finding a way of attaching and detaching the
lift line - the cable which connects the vehicle to the MOSHIP A-frame
while it is lowered or retrieved - without the use of divers and swimmers
with the safety and speed restrictions they impose on an operation. A
way has to be found to do this without adding to the rescue submersible's
topweight.
On the logistic side of the equation, the forthcoming procurement of the
A400-M transport aircraft with its 32-ton payload is shifting favour away
from the C-130. Options are also to be looked at and costed for possible
MOSHIPS. Should VOOs be used, current naval vessels be modified, new build
vessels 'fitted-for-but-not-with' or dedicated MOSHIPs included in the
system?
"In a nutshell," concludes Cdr Burston, "we now want to
take the User Requirement Document and turn it into a Systems Requirement
Doc-ument. This would produce five or six shapes for NSRS, which can be
debated later. There's nothing technically complex about building a cost-effective
system - the problem is the multitude of different scenarios it might
be used in... especially because there are more submarine operations in
littoral waters with the risks they present.
"We do have a real determination to go ahead and produce this system,"
he adds. With 192 launches to his name, submarine rescue pioneer Cdr Ryan
agrees. "In a way, in submarine rescue we are all crusaders,"
he remarks. "It will be fascinating to see the fruition of the NSRS
project, and the more visibility it gets, the better." Though the
prospect of another real-life DISSUB event such as the Kursk incident
is no-one's wish, submariners can rest assured that rescue crews will
be ready. "I cannot see any scenario," says Cdr Hoskins of the
UK SERP, "where if we know that submariners are still alive we won't
try to rescue them."
Related external links:
www.kurskfoundation.org
Rumic
US
Submarine Rescue
General
info
 |
Norwegian
divers finally prised open the escape hatches on the Kursk nine days
after it sank, only to find the submarine had flooded with the loss
of all hands. Had a co-ordinated rescue effort arrived on the scene
within 72 hours, would lives have been saved?
(Source: PA News; graphic: J Pye/Jane's) |
 |
The
Antonov An-124, seen here with the LR5, is becoming a popular choice
for airfreighting submarine rescue systems.
(Source: MoD/Crown Copyright) |
 |
The
UK's LR5 rescue vehicle is raised onto its A-frame ...
(Source: UK MoD/Crown Copyright) |
 |
And
lowered into the sea from the back of a MOSHIP. The air-portable A-frame
weighs 25 tons and takes about 10 hours to fit onto a suitable deck.
(Source: UK MoD/Crown Copyright) |
 |
The
'McCann' diving bell operated by Turkey, Italy and the US may be antiquated,
but proved an effective system during 'Sorbet Royal 2000'.
(Source: NATO) |
|
|
The
interior of an SM-5 D12 Submarine Escape and Rescue Decompression
System recently purchased by a southeast Asian navy. This design,
capable of taking 50 occupants at a time, has a TUP arrangement and
may influence future equipment such as the US SRDRS.
(Source: Southern Oceanics, Cape Town) |
 |
 |
Two
early concepts for the NSRS, an RORV-type design. An actual design
for the system should be ready in 2003, for an in-service date of
2005.
(Source: DPA/NSRS-IPT) |
 |
Swimmers
are required to hook the LR5 to its A-frame, a restriction the NSRS
design may be able to eliminate.
(Source: HM Steele/Jane's) |
|
|
| The
US Navy's second DSRV, the Mystic, was built in the early 1970s and
is shortly to be retired. Trials on a new RORV system for the US are
expected in 2003. (Source: USN COMSUBPAC) |
End of non-subscriber extract
