OIL TANK STEAMERS
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Pipe Lines, Deck Steam-pipes, Tank-tops with Guard Rails, and
Fore and-aft Bridge ou modern Tanker. Note davit for
supporting oil hose.
Tank-tOiis showing Butterfly Screws and Plugs ; Valve Wheels shown.
Deck Pipe Line in foreground.
7s. 6d. NET
OIL TANK STEAMERS
Their Working and Pumping
30 CHAPTERS, WITH 13 DIAGRAMS, AND NEW TABLE?
FOR CALCULATING WEIGHTS OF OIL AND WATER
Captain HERBERT JOHN WHITE
JAMES BROWN & SON, Printers and Publishers
52 TO 58 Darnley Street
o",.» r , • .-
V N 4-Sd-
T^HIS little book has been written by an officer
on board an up-to-date oil tank steamer, in
an endeavour to explain to those just starting — or
who would like to start — in these ships, but who
hesitate because they know that the work is entirely
different, and there is no standard book or manual
to give them the necessary guidance when first
starting. I have been gready assisted by Mr. J.
D. Nesbitt, a brother officer, whose knowledge
of oil tanks is from A to Z.
Any hints or criticisms for bringing up to date
future editions will be gladly welcomed by the
HERBERT JOHN WHITE.
PREFACE TO SECOND EDITION.
TX introducing' the second edition of Oil Tank
Steamers on to the market, I wish to thank
my many correspondents who have helped to make
the first edition such a complete success.
This edition fully describes eleven different types
of tank steamers, and a diagram is given to illustrate
The carriage of different kinds of oil is fully dealt
with, and at the end is inserted a new table for
calculating weights of oil or water. This table has
been tested by experts in England and America,
and is claimed to be the simplest and quickest
method ever published.
Any descriptions of new improvements or useful
information will be welcomed by the Author to
improve future editions.
HERBERT J. WHITE.
I. Arrangement of Tanks, Cofferdams, and Pump-rooms,
with Diagram i . . . . • .
2. Summer Tanks and Expansion Trunk
3. Pipe Lines, Valves, and Crossovers, with Diagram 2
4. Pumping Arrangements of the Summer Tanks .
5. Pump-rooms and their Valves, with Diagram 3 .
6. Water Ballasting and Shifting Ballast
7. Cleaning Tanks for Cargo ....
8. Different Kinds of Oil
9. Flash Points, Specific Gravity, Viscosity and its Effects 46
10. Measurement of Tanks, taking Ullages and finding
Quantities ........ 50
11. Flexible Hoses and their Connections ... 56
12. Blank Flanges in Pipe Lines, with Diagram 4 . . 59
13. Tanker with Small Pump-room, with Diagram 5 . 69
14. Old Type Tanker, Single Pipe Line, with Diagram 6 . 75
15. Tanker with Single Suctions, with Diagram 7 . .80
16. Tanker with Engines Amidships, with Diagram 8 . 85
17. New Tanker with Single Pipe Line, with Diagram 9 . 89
18. Converted Ship fitted with Circular Tanks, Diagram 10 94
19. Standard Type Tank Steamer, with Diagram 11 . 98
20. Tanker with Two Valves on each Suction, with
Diagram 12 . . . .... 103
21. Tanker with Three Pipe Lines on each side, with
Diagram 13 ...... 107
OIL TANK STEAMERS.
2 2. The Carriage of Kerosene .
23. The Carriage of Creosote .
24. The Carriage of Spirit
25. The Carriage of Lubricating Oil
26. The Carriage of Fuel Oil .
27. A Few Hints on Gas
28. The Importance of Temperature
29. Miscellaneous Information
30. Table for Calculating Weights of Oil or Water
ARRANGEMENT OF TANKS, COFFERDAMS AND
\ TANK steamer is one which, as its name
^^ denotes, is divided into tanks. It is divided
by a longitudinal bulkhead at the middle line through
the whole length of the cargo part of the vessel, the
bulkhead, extending from the tank bottom up to the
deck. The vessel is also divided by athwartship bulk-
heads, which extend from one side of the ship to the
other, thereby forming the tanks.
in large modern tankers, there are generally
twelve double tanks, two pump rooms, and twc
Starting ri^ht forward in the ship, there is first
the fore peak with a watertight bulkhead at its
after end. Next abaft this, is the fore hold, which is
intended for any cargo the vessel is to carry besides
At the after end of the fore hold is an oiltight
bulkhead, extending from side to side, and from
the bottom of the ship up to the deck above.
This cuts off the fore hold from the oil tanks. Abaft
OIL TANK STEAMERS.
this bulkhead, and 5 feet awav, is another oiltiaht
bulkhead similar in construction, these two bulk-
heads making an oiltight space which is called
a cofferdam. When carrvino^ dansferous oil tliis
cofferdam is filled with water, thus makino- a
solid body of water between the fore hold on the
forward side of the cofferdam and the oil tank 0:1
the after side of the cofferdam.
There is a small pump room for this forward
section of the ship, which is for this section of the
ship alone. The small pump it contains deals with
the fore peak, the fore deep tank (which is situated
under the fore hold), and the cofferdam. Thus the
forward section of the ship is entirely isolated from
the oil cargo tanks.
The cargo tanks are conveniently numbered from
aft and run from i to 12 ; so the forward tank is
called No. 12 port and No. 12 starboard. This
is the tank next abaft the cofferdam which has
already been described.
Coming aft from No. 1 2 tank, we have tanks 1 1
10, and 9. On the after side of No. 9 tank we usually
have the forward pump room. It contains two big
cargo pumps, one on the port side and another on the
starboard side. The after bulkhead of No. 9 tank,
which forms the pump room forward bulkhead, and
the after bulkhead of the pump room, which forms
the forward bulkhead of No. 8 tank, are oiltioht,
OIL TANK STEAMERS. 3
thus making an oiltight compartment between No. g
and No. 8 tanks.
Proceeding aft, wc have the tanks 8, 7, 6, and 5
and on the after side of No. 5 tank we have the after
pump room. This is similar in construction to the
forwaid pump room, and also has two big cargo
pumps and an air pump which will be described
later on, the after bulkhead of No. 5 tank forming
the forward bulkhead of the after pump room, and
the forward bulkhead of No. 4 tank, forming the
after bulkhead of the after pump room.
Continuing aft, we have tanks Nos. 4, 3, 2, and i.
On the after side of No. i tank is an oiltight bulk-
head, which is pierced by the pipe line on the port
side only ; this really finishes the oil cargo tanks.
The next tank abaft No. i is generally known as
Lhe cross bunker tank, which, if the vessel burns oil
fuel, is used by the engineers as bunker space. If
the vessel burns coal, then this tank is also used for
cargo if required.
At the after end of this cross bunker tank is an oil-
tight bulkhead extending from side to side and from
the tank bottom to the deck above, and at a distance
of 5 feet further aft is a similar bulkhead. The
space between these two bulkheads forms the after
cofferdam., which, when a ship is carrying any
dangerous oil in the cross bunker tank, is filled with
water, thus making a 5 -feet thick bulkhead of water
4 OIL TANK STEAMERS.
between the tanks on the forward side and the
stokehold on the aft side. Thus the stokehold and
engine room (which is abaft it)' are absolutely shut
off from the tanks containing" oil.
A careful study of diagram No. I. will show exactly
how the tanks, pump rooms, and cofferdams are
C(}/=r£» DA Mi
VLL TANK STEAMERS.
SUMMER TANKS AND EXPANSION TRUNK.
T]iE question naturally arises, " How do you stop
the oil from rolling, even though each tank has its
longitudinal bulkhead at the middle line."
This is effected by filling the oil up into the
expansion trunk of the tank. The expansion trunk
could almost be correctly called " the contraction
trunk," seeing that it is the smallest part of the tank.
It is formed by the summer tanks in the follow-
ing way ; — In each tank, and out in the side, is built
another small tank close up under the deck, and
extending about 15 feet from the ship's side towards
the middle of the ship. It is about 8 feet in depth,
and runs the whole lengrth of each tank fore and aft.
To describe it by name it could be correctly called
" a wing tank," from its situation up in the " wings "
of the main tanks.
It is entirely separate from the main tank in which
it is situated, and has its own little hatches, opening
up to the deck above, and also its own pipe line
arranoements. Thus it will be seen that from the
top of the main tanks 10 a depth of at least 8 feet
down (which is the level of the summer tank bottom)
6 OIL TANK STEAMERS
each main tank is reduced in breadth by 15 feet owing
to the presence of the summer tanks.
This, the smahest part of each main tank, is called •
" the expansion trunk." ^Vhen the main tanks are
loaded it is always the rule to fill them at least
up into the expansion trunk some 4 or 5 feet. Thus
below the expansion trunk is a solid body of oil, which
therefore cannot roll. The only quantity which can
roll is the small quantity in the expansion trunk. A
glance at diagram No. I. will show the position of the
The expansion trunk of a tank is never filled right
up to the top, but usually there is a vacant space
between the top of the oil and the top of the tank. The
measurement of this space is called the "ullage."
When oil is at a higher temperature it expands, and
when its temperature falls it contracts, so a vacant
space is left at the top of the tank when loaded to
give room for the oil to expand. Thus does the top
part of the tank derive the name of "expansion trunk."
Oil expands to per cent, for every degree the tempera-
ture is raised, and will contract 2V per cent, for every
degree the temperature falls.
If a vessel uses coal as fuel, then most of the
summer tank space would be used as bunker space.
It is advisable to leave the description of the summer
tank pipe lines and pumping arrangements till after
the main tank pumping arrangements have been
OIL TANK STEAMERS. 7
explained, in order that anyone can get a g-ood
knowledge of the main tanks; after this the summer
tanks are quite simple.
Each summer tank has its own hatch, and some-
times more than one, and these hatches form the
•' expansion spaces of the summer tanks."
OIL '1\\NK STEAMERS. 9
that in the forward end of No. 12 tank these two
pipe lines are connected by a big pipe line running
athwartships, which crosses over from one line,
through the middle line bulkhead, to the other line.
It is named the forward cross over.
Looking next at the forward pump room, we find
there are two cross over lines runnino from one side
to the other. One is at the forward end of the
pump room, and one is at the after end of the pump
room. These two pipes are called the forward
pump room cross overs.
Looking at the after pump room, it is seen that
there are also two cross over pipes there similar to
those in the forward pump room which have just
• been described.
There is one more cross over line to be described,
and this is situated in No. i tank. It is similar in
construction to that in No. i 2 tank.
Thus along the whole length of pipe line we have
six different cross over lines, by which we can draw,
or pump, from one line to the other.
Again examining the diagram, we see the pipe
lines pass through each tank, and branching out
from them we see short pipes which are called
suction pipes, because by these pipes we draw the
oil from the tanks into the pipe lines, and along
them to the pumps.
Taking No. 10 tank first for an example, and
\o OIL TANK STEAMERS.
Starting with the port pipe Hne, we see that
branching out from this Hne there is a short suction
pipe which ends in the port side of the tank. This
pipe is called "the port suction on the port Hne."
Its name explains exactly what its work is ; to draw
from the port side into the port line.
Branching out from the port pipe line is a longer
suction pipe which crosses the port side of the tank,
and goes through the fore and aft middle line bulkhead
into the starboard side of No. lo tank. By this pipe
we can draw from the starboard side of the tank into
the port line. This one is called "the starboard
suction on the port line."
Next, looking at the big starboard pipe line as it
runs through No. lo tank, we see that this line
also has two suction pipes branching from it. The
short one ends in the starboard side of the tank,
and is called the "starboard suction on the star-
board line," because it drawls from the starboard
side of the tank into the starboard pipe line. The
other suction pipe crosses from the starboard side of
the tank, goes through the middle bulkhead, and ends
in the port side of the tank. This is called "the
port suction on the starboard line," because it draws
from the port side of the tank into the starboard
line. After looking at the diagram the reader can
grasp the system at once.
If this arrangement is learned for one tank it
OIL TANK STEAMERS. ti
applies to every one of the main tanks. These are
the four essential suctions in each tank which an
officer must know ; the port and starboard suctions
on the port line, and the port and starboard suctions
on the starboard line.
So far, only pipe lines and suction pipes have been
dealt with ; now it is necessary to describe the valves
whereby the oil is either admitted into the pipe lines
or, with the valves shut, is kept in the tanks.
Near the end of the suction pipes (described above),
where they are open into the tanks, is fitted a valve
which works up and down in a socket fitted in the
suction pipes, according as they are turned from the
deck above. These valves have attached to them
a long spindle which goes up through the tank top,
and is worked from the deck. If the valve is screwed
upwards it opens the suction pipe into the tank, and
if it is screwed down again it blocks the suction pipe
from the tank. It acts exactly the same as a sluice
valve on a bulkhead. By screwing up the sluice
valve you uncover the hole and allow liquid to flow
from one compartment to the next, and by screwing
down the sluice valve you cover up the hole and
stop the flow of the liquid, and this is exactly on the
same principle. By opening a valve the oil is
allowed to run from the tank into the suction pipe,
and thence into the big pipe lines, and so to the
pump. By screwing down a valve the hole in the
12 OIL TANK STEAMERS.
suction pipe is blocked, so that the tank is shut ofif
from the pipe h'ne and pump. By looking at a valve
open and shut the reader will grasp the meaning at
It must be mentioned that ail suctions are situated
near the after end of the tanks, so that it is essential,
when draining the last oil from a tank, to trim the
ship " by the stern," so that any oil left will drain
towards the suction at the after end. The end of
the suction pipes are fitted with rose boxes, which
only allow liquids to pass through to the suction pipe,
and keep out any dirt or floating refuse which may
have got into the the tank, and so prevent the
choking of the valves or pipes. To properly drain
out tanks, the ship must be slightly listed away from
the side you wish to drain. For instance, if drain-
ing tanks on the port side, list the ship tw^o or three
degrees to starboard, and any oil left in the port
side will run towards the middle line where the
suctions are situated.
Before finishing with the pipe lines, it must be
stated that there are valves called master valves on
the pipe line itself in different places which shut off
one section of the pipe line from the next as may be
required. The first two master valves are situated
on the cross over lines. One is fitted exactlv at the
middle line in the No. 12 tank, thus dividing the for-
ward cross over line, and the other is situated in the
OIL TANK STEAMERS. 13
same relative position in No. t tank, on the after cross
over line. By opening these two master valves it is
possible to pump right round the .ship.
For instance, with these valves open, if pumping
be started with the starboard after pump alon«: the
starboard line, the oil will flow through the forward
cross over into the port line. It will then go right
aft to No. I tank, and through the cross over there,
and then into the starboard line again, next arriving
at the place it started from.
By keeping these two master valves shut, it com-
pletely isolates the port and starboard lines from each
other at the forward and after ends.
There are other valves on the pipe lines, situated
under the pump rooms. These will be dealt with in
the chapter devoted to the pump rooms.
The next thing to consider is how to distinguish
the different valves, because if the wrong one is
opened it might be a serious thing, and different
kinds of oil might get mixed. The standard rule for
distinguishing valves is to paint them in different
colours. So the valve spindles (on the deck above
the tanks) are painted, the two suction valves belong-
ing to the port line being painted red, and the two
suction valves belono-ing to the starboard line are
painted green. Thus, there is litde possibility of a
mistake if you remember which line you wish to use.
For instance, it would be useless to open a green
14 OIL TANK STEAMERS.
valve if you were pumping on the port line, as the
green, valve would only open a valve on the starboard
Now, besides these four valves already described
which are most important to know, there are
also two steam valves, one for each side of the
tank, and also two air valves, one for each side
of the tank. The air valves are painted black
and the steam valves arev painted white. On look-
ino- at the valves which belong to a tank, the
different colours will at once show what valves
Air valves and steam valves have now to be
explained. In the after pump room there is a big
air fan driven by steam to help to clear the tanks
of gas. The air is driven by the fan down into the
main pipe line, and by opening the air valve of the
tank you wish to free from gas, the air will rush in
and drive the gas upward and out of the top of the
tank. By opening the air valve which is fitted on
the suction pipe, the air is allowed to blow freely
into the tank. We could also open the suction
valves for that tank and allow the air to come
in, but seeing that the end of the suction pipe is
covered by the rose box, the force of the air would
be checked and not have a free oudet, so the air
valve is opened and the draught comes right into
the tank with its full force.
OIL TANK STEAMERS. 15
The next thino- is the steam valve. On lookincr
down into an empty tank, you will notice, right
on the bottom, a coil of small pipes running all
over the bottom of the tank and spreading in all
directions. These are the steam heating pipes
used for heating the cargo if required, and the
white painted valves above mentioned turn on the
steam into these coils in the tank whose valves are
opened. Thus the cargo in the tank is heated and
kept at the required temperature. Of course, it is
never necessary to heat light oils, such as petroleum,
naphtha or gasolene. You are always glad to see
their temperature go down.
In considering this question of temperature, the
writer has found by experience that the tempera-
ture of the- oil in the tanks is regulated by the
temperature of the sea water outside the ship. As
the ship comes into colder water, so the temperature
of the oil in the tanks decreases. Generally
speaking, the tank temperature is about one degree
above the sea temperature. Light oils quickly
come down to the normal temperature when
pumped from shore into a ship's tanks, but heavier
oils take longer to cool down.
A few words why oil sometimes needs to be
heated will not be out of place here. If proceeding
to a colder climate where the sea temperature is
low. the heavier oils will gradually lower in
i6 OIL TANK STEAMERS.
temperature and contract into a smaller space,
thereby becoming thicker. This would make it
much harder work for the pumps, which always
show the best average and work much easier
when the oil is thin ; so the policy is to keep
up the temperature of the oils by circulating steam
through the steam coils in the bottom of the tanks.
Before finishing about valves, it is to be under-
stood that the valve spindles come up through
the deck (which forms the top of the tank) for a
distance of 2 feet. The ends are square so as to
enable a spanner to be fitted on to turn them. In
some ships ratchets are used, and in others box
spanners or wheels are used for opening and shutting
In up-to-date tankers, all tank valves are left
handed ; that is to say, they turn to the left to shut
down and turn to the right to open. All valves
are situated at the after end of the tank to which
Each main tank is provided with a hatch for access,
which has a coaming extending about 18 inches above
the top of the hatch, and which is sealed by means
of a steel lid or cover. Round the edge of the cover,
which slightly overlaps the coaming, there is a recess
fitted with some suitable packing material. When
closing- the hatch the lid is forced down by means of
bolts having butterfly nuts, which are fitted at
OIL TANK STEAMERS. 17
intervals round the top of coaming until the packing
is bearing on top of the coaming plate at all points.
The hatch is then thoroughly oil tight.
When loading or discharging one should always
be careful to see that the air plug which is fitted on
each hatch lid is open ; that is, if the lid is not lifted
up. In discharging a tank, if there is no place for
the air to get in to the tank to fill the vacant space
caused by the oil being pumped out, a big vacuum
would be caused and it would be impossible to raise
the lid or take the plug off.
In loading oil cargoes there must also be a place
for the air to escape, as the oil comes into the
tank from the pipe lines.
If an escape is not made for this air, it would
become so compressed that it might force something
to give way.
i8 OIL TANK STEAMERS.
PUMPING ARRANGEMENTS OF THE SUMMER TANKS.
Having studied the pipe lines and valves in the
main tanks, we will now mention the pumping
arrangements of the summer tanks, or wing tanks,
as they might be called.
The summer tanks run the full length of the main
tanks below them, in their fore and aft direction,
and project in from the ship's side about 15 feet.
This summer tank space is, in the vessel under
consideration, divided by transverse bulkheads into
five summer tanks numbered i, 2, 3, 4 and 5; being
numbered from aft. Each tank is separated from
the next, and the bulkhead is only pierced by the
summer tank pipe lines and steam heating pipe.
First we will consider this little pipe line as it
passes through the summer tank and leave its
connection with the main pipe line till later.
Its forward end is in the after end of No. 5 sum-
mer tank, where it has a suction valve which, when
open, allows the oil in this tank to enter the pipe line
to be discharged, and when shut keeps the oil in the
tank so that it will not run out through this pipe
line. This pipe line passes through all the summer
OIL TANK STEAMERS. 19
tanks, and at the after end of No. i summer tank
connects on to the Hne which goes down to the main
pipe line below. On this line, in every tank excep/
No. 5, there is a master valve at the after end of the
tank. This description applies to both sides alike.
Situated at the after end of No. 4 and No. 2 summer
tanks is a small pipe branching out from the pipe
line. It goes towards the ship's side, and then turns
downwards through the tank bottom and protrudes
into the main tank situated below it. This is the
drop pipe. On this short pipe there are two valves.
The first one is the suction valve for this tank, and
the other goes down through the tank bottom and
works the valve on the end of the drop line. This
valve is called the drop valve. By opening this drop