TO SEE THE ELECTRICAL SYSTEM
Balmoral's correct title is 'M.V. Balmoral'. The M.V. is short for
motor vessel and is one of a number of prefixes used to describe how a ship
is powered or what it is intended to do.
Examples of these are as follows
PS - paddle steamer
SS - steam ship
PSS - paddle screw ship - (there was only one, the Great Eastern )
TSS - turbine steam ship
MV - motor vessel
ML - motor launch
RMS - Royal Mail ship ( carrying UK postal deliveries )
FV - fishing vessel
HMS - Her Majesty's Ship ( naval vessel )
In this case Balmoral is an MV as she is powered by diesel engines as
opposed to steam engines like some of her predecessors.
STEAM V DIESEL
Diesel engines are very much more efficient than steam engines as they
are smaller and don't need huge boilers and complicated piping systems and
condensers to return steam to the boilers for reuse. Diesel engines are also
smaller for the same power output and just need fuel oil - also known as
'gas oil' ( not the same as gasoline which is the American word for petrol
), they don't need a constant supply of fresh water to turn into steam and a
complicated system of burners to heat the boilers. This means that as
well as being cheaper to run, the engines take much less space in the ship,
so for a given size, you get a lot more load carrying space. Diesel
engines also use much less fuel as they are more efficient at turning energy
from the diesel oil into motive power. In a steam engine around half
of the energy is lost up the funnel as waste heat, whereas a diesel converts
around two thirds. This makes a diesel engine ship cheaper to run and
more economic. There are still cases where a steam engine is more cost
effective, but this is very rare and only applies to very large ships fitted
with steam turbines. In general steam powered ships are either used
because they are historic or as leisure vessels for passenger service.
Other advantages of a diesel are that it starts immediately; a steam ship
can take many hours to raise enough steam to turn the engines, the engine is
much faster to respond to the controls , needs far less maintenance and does
not generate huge amounts of heat inside the ship. The disadvantages
are noise, vibration and in some cases the need to reduce the speed of the
final drive as the engine turns too fast for a propeller to be efficient,
although in the case of the Balmoral's original engines they turned slowly
enough to coupled directly to the propeller shafts.
BALMORAL'S FIRST ENGINES
As she was built, Balmoral was fitted with two Newberry
Sirron six cylinder direct reversing 2 stroke diesel engines.
These were made by the Russell Newberry Company and were designed by a man
named H Kent-Norris, who was an engineering graduate of Bristol
University. The company reversed his name to make Sirron, and that
name was used for a range of highly successful marine 2 stroke diesel engines.
The ship was originally intended to have 8 cylinder engines and a higher
speed, but a cost saving was made by reducing the power and fitting
smaller engines. This gave more space in the engine room but also
meant that the ship was more heavily built. This has helped her to
survive over half a century of hard use - and in later years the extra space and
layout of the engine room enabled new more powerful engines to be
The original engines were 2 strokes but not like a petrol bike or chain saw engine.
They did not need oil mixed with the fuel - and they were diesel anyway -
but rather than having valve gear, the engine had a large air compressor
that used high pressure air to push the exhaust gas out of each
cylinder with each turn of the crankshaft. This meant that compared with
a 4 stroke engine with valves, the engine had double the number of power
strokes in each cylinder - in a four stroke engine there is a power stroke
every other cylinder cycle, but with a two stroke there is power on every
turn of the engine. This gave a much higher power to weight
ratio, so for the given size of the engine, the ship could go faster.
As she was being used as a ferry on the Southampton to Isle of Wight
Service, this was not important on her day job, but it certainly was when she was used for
her other purpose, that of a passenger cruise ship when she needed to take
holiday makers along the South Coast. Then the additional power of her
engines was very useful and the ship could make 16 knots.
Each engine appeared to have an extra cylinder, but the one at the
'front' was actually the compressor for the scavenging system that cleared
exhaust from the cylinders.
This can be seen on the left photograph with the large
circular cover on top.
These evocative photographs by Richard Mills bring back the noise, heat
and wonderful smell of warm oil as Balmoral's two Sirrons push her up
Channel on a chilly Autumn Evening towards the lights of Weston super Mare.
Note the spare piston and con rod on the brackets above the Starboard
The engines may have been powerful, but being 2 stroke they were not as
efficient compared to a modern 4 stroke engine and created a lot of smoke at full speed as the fuel was not
burned very efficiently, so Balmoral always had a dirty funnel and her smoke
was a feature of the ship. As she got older, her consumption of
lubricating oil increased dramatically and towards the end of her time with
P & A Campbell on the Bristol Channel, she was always seen with 200 lts
drums of Shell 'Rotella' marine lubricant in the engine room alleyways,
ready for topping up her tanks. ( model photograph below ).
The engines were direct coupled to the propeller shafts, and to go
astern, the engine was stopped and started again in reverse. It was a
very simple way of operating the ship, and stopping and restarting was very much faster than slowing the engine down, shifting gear and
then speeding it up again. She did not need a gearbox or reversing
system and as the engine had no valves, it ran just as efficiently in either
direction. This made a much cheaper and lighter installation and saved
money, servicing costs and maintenance. The engines were started by
compressed air and there was a large cylinder beside each engine that
provided a number of starts. As each ahead/astern manoeuvre
required a blast of air and she had two big engines, this gave a finite
number of engine commands before the air supply was exhausted. If the
Captain messed up an approach to a pier, perhaps in bad weather and had to
have another attempt, it was sometimes possible to hear the engine room
warning siren go off, indicating that the air pressure was getting low.
In this case Balmoral would have to give up trying to go alongside and
steam round the bay for a while until there was enough pressure in the tanks
to continue manoeuvering. She had a separate compressor to top up the
air tanks for starting from cold, so she was never unable to operate,
but as she was intended for use in the Solent which is a sheltered area, the
designers never anticipated she might run out of compressed air during the
complicated engine movements needed for some Bristol Channel piers, Weston
being the most difficult.
For more information on the Newberry Sirron range of engines,
As already described in the section on the bridge, the engine commands were
signalled to the engineers by means of a telegraph dial indicator with a back
up of lights plus a bell and finally a speaking tube. This
required an engineer to be at the controls of each engine whenever the ship
was near a pier of harbour. On a modern ship the captain can
control the engines directly with a control on the navigation bridge, but
with the telegraph system, everything had to go via the engineer who set the
engine controls in accordance with the captain's instructions.
Although it was found that the Sirron engines originally fitted to Balmoral
were about 5 seconds faster to react than her later engines that had
gearboxes, there is always the impression that using telegraphs and
engineers to respond to instructions removed some of the direct response
that can be achieved if the engines are under direct bridge control.
However in practice this is not the case. While it does mean that two
duty engineers need to be available, when the Captain and his
engineers had worked together for some time, it was claimed that a
good team could interpret the way the telegraphs were rung by the Captain
and as a result he had better control of the ship as the engineers were able
to interpret his commands far better than if he just moved a lever on the
The photographs below show Balmoral in 1975 with her Sirron engines.
They were noisy, dirty and not particularly fuel efficient, but they were
incredibly reliable and never once let the ship down when in service.
When they were changed in 2003 the engines were initially given to a museum
but were found to be completely worn out and were scrapped. This was rather
sad as there are not many types of this engine left.
During a voyage, only one engineer needed to be on station at the
controls but two had to be immediately available - one for each engine !
The controls for the Starboard diesel can be seen on the back of the
The tank on the walkway is a portable fire extinguisher !
A common site in the Campbell's days - a piston and associated piston
rings on the engine platform ready to be fitted during an off service day.
The engineers not only operated the machinery but did the servicing each
winter and it was not unusual for a major job to be undertaken during the
ship's weekly day off duty !
The large white pipe behind the piston rings is the insulated exhaust
pipe leading to the funnel above.
In 2003 Balmoral was fitted with two 4 stroke Danish built Grenaa diesel
engines with separate gearboxes and new propellers.
These were more powerful and much more fuel efficient, giving the ship an
extra 2 knots in speed.
Engineer control was continued but new emergency signalling was installed
and the engines are much more economic to operate.
Each engine has its own log book and full maintenance records as can be seen
in this photograph. The gearboxes are under the 'tables' and the
photographer is standing between the engine controls.
This is the engineer's position for the Port ( left ) engine. You can
see the main telegraph, the emergency communication system and the brass
topped pedestal with the engine and gearbox control lever on top. The main
engine instruments are on the black board. To the right of the control
pedestal is the main gearbox with the shaft coupling under the white
circular cover. You can see the silver propeller shaft as it heads
towards the stern of the ship.
The engine room is a mass of pipes, tanks , diesel engines and electric
motors of various shapes and sizes ! In the lower photograph are three
Lister Diesels from 1949 - Two electrical generators and a compressor
to supply high pressure air for starting the main engines.
For a short video of the engine room :
Machinery & Engines