Fuel Systems &= nbsp; &nbs= p; &= nbsp; Chapter
10
All system= s start with fuel. Keeping clean fuel= and supplying it effectively is like eating.&n= bsp; Do it wrong and nothing will work.=
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uel management requires loading fuel, transferring it among the tanks and delivering it to the engi= nes and furnace for system operation. The ship has six tanks. Two large bunkers and a smaller day tank on each side of the ship. There is a fill station in the coc= kpit and a dispensing station on the swim platform. Fuel is loaded and transferred amo= ng the tanks from the transfer manifold. The two day tanks are plumbed to the supply manifold for distributio= n to fuel consumers.
Fuel Tanks
The ship’s fuel tanks are located in the doubl= e hull on each side of the bilge under the soles of the staterooms. Each tank is internally baffled an= d has a clean out access hatch in the cabin sole. To drain off condensation, each ta= nk has a sump drain at the low part which is accesses from the bilge. Each sump should be purged regular= ly to prevent the build up of water and sludge.&= nbsp; Fuel is transferred into and out of tanks using a single transfer pipe. These pipes are routed = to the suction and fill manifolds in the engine room. A shut off valve is located at the entrance to each tank. This v= alve should usually remain open. I= n the event of an engine room fire, fuel from all tanks to the manifold can be sh= ut off from these valves.
The level in each tank is sensed by a solid state se=
nsor
and connected to the Computank display system. This gauge has been calibrated wit=
h each
tank’s geometry so that it can read out the tank levels in gallons.
The locations of all of these components and the tank capacities are shown in the following table.
Table x – Fuel Tanks
|
Tank |
Capacity (=
gal) |
Sump |
Sensor |
Pick-up/ s=
hut-off/
fill |
Vent |
Clea=
n-out
access |
|
Port forward
bunker |
1250 |
mid-bilge under stairs |
port state room under bed |
mid bilge by stairs |
Along hull to port locker in Portuguese
wall |
Under PSR bed |
|
Port mid bun=
ker |
1250 |
MSR bilge forward |
under MSR bureau by forward door |
MSR bilge forward |
along hull, joining forward vent |
MSR by port nightstand |
|
Port day tan=
k |
250 |
Utility room bilge |
Utility room |
Utility room |
Along hull joining mid tank vent |
Utility room |
|
Starboard
forward bunker |
1250 |
Mid bilge under stairs |
Under stairs in access panel outside M=
SR
door |
Mid bilge by stairs |
Along hull to starboard locker in
Portuguese wall |
Office under desk |
|
Starboard mid
bunker |
1250 |
MSR bilge forward |
MSR head in access panel in wall by to=
ilet |
MSR bilge forward |
along hull, joining forward vent |
MSR by utility door |
|
Starboard day
tank |
250 |
Utility room bilge |
Utility room |
Utility room |
Along hull joining mid tank vent |
Utility room |
Fuel Transfer
Fuel can be transferred between any two tanks on the ship. The pick-up/fill line f= rom each tank is plumbed to the transfer manifolds on the forward wall of the engine room. The transfer sys= tem consists of a suction manifold, a filter bank, redundant fuel pumps, and a return manifold to select the desired fuel destination. To transfer fuel, a source tank is selected on the suction manifold, select a pump, and then select the destination on the return manifold. Operate the pump to transfer the fuel.
Typically the fuel should be filtered whenever transferring among tanks. If = the fuel is known to be very clean, e.g. it was recently filtered; the filters = can be bypassed with the valve at the aft end of the filter bank. This it not recommended.
The manifold is sized sufficiently to handle the suc= tion from both pumps, when in this mode there must be two suction and two return tanks selected. The exception= is both pumps may be used to suctioning from the fill buffer, but two return t= anks must be selected. This is use= ful to speed fueling operations.
The sight flow indicator at the input of each pump w= ill indicate the flow of the pump. This sight flow indicator should begin to show rotation almost as soon as the pu= mp is switched on. If fuel has n= ot been transferred for some time the pump may have to create a suction to pri= me, but it should be less than 30 seconds.&nbs= p; If the pump continues to run and the sight flow indicator does not s= how rotation either the valves are incorrectly arranged or the level of the fue= l in the ‘from’ tank is too low for the pump to pick-up. Check the valves and try aga= in. If the pump runs dry long enough f= or the housing to get hot, the impeller will likely be damaged.
All fuel is pumped through the large stainless steel canister filters (Perfect Filtration) in the fuel space when loading or transferring fuel. There is a vacuum gauge on the top of one of the filters. Change the filters when this gauge reads in the red. Also change the O-ring= at the top of the filters at the same time as changing the filters.
![](3D"Fuel_files/image002.gif")
Fuel Fill
Filling functions like a transfer, except that the f= ill buffer valve on the ceiling above the transfer manifold is opened instead of one of the other tanks. The <= span class=3DSpellE>fueler fills the buffer using the sight glass on the = buffer tank and the pumps are used to draw fuel out of the buffer. This involves one person to monito= r the buffer and one to monitor the transfer station and tank levels.
The fuel fill is from the buffer tank on the starboa= rd side of the aft cockpit.. The fill tube is behind the upper = door along with a vent. A site gla= ss for the buffer tank is behind the lower door.&= nbsp; The fuel from shore should be pumped at a rate to keep the buffer ta= nk half full while the pumps at the transfer station drain the buffer. The buf= fer tank site glass valves must both be opened to obtain readings and closed wh= en not in use.[WW1]
Fuel Delivery
Fuel is delivered to the engine, generators, furnace=
, and
dispensing station from the delivery manifold in the utility room bilge.
Diesel engines and the furnace draw more fuel from t= he lines that they require. Exce= ss fuel is returned to the day tanks. The engine and furnace return to the starboard day tank and the generators return to the port day tank.&nb= sp; If a piece of equipment is operating it is important that the tank t= hat receives the return is supplying the delivery manifold, or tank over flow c= ould result. Generally both day ta= nks should supply the manifold to keep the ship trim as fuel is consumed.
Fuel Filling Checklist=
WARNING: Over filling any of the tanks can result in fuel pumped = out the fuel tank vents causing a fuel spill in the surrounding waters. This = is a serious offense and may result in a fine of several thousand dollars plus clean-up costs |
Fueling operations can direct fuel to any of the tan= ks or several simultaneously.
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NOTE: Fuel Tank monitor is programmed = to show 100% full when the tanks are completely full. Only fill tanks to 90%= . Note: NEVER close = all tank inlet valves before stopping the Fuel Transfer Pump. Fuel will continue to fill the S= urge Tank, but cannot enter the Fuel Tanks. |
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NOTE: If you wish = to use both Fuel Transfer Pumps at once, for faster filling or transfer, you must have at least two discharge valves and two tank inlet valves open. |
Fuel Transfer Checklist
WARNING: Over filling any of the tanks can result in fuel pumped = out the fuel tank vents causing a fuel spill in the surrounding waters. This = is a serious offense and may result in a fine of several thousand dollars plus clean-up costs |
Fuel can be transferred from one tank to another for= use, to change trim, or to clean the fuel if it is suspected of being contaminat= ed.
CAUTION: If both day tank drain valves are open, both day tanks will fill simultaneously. Therefore, = both tank levels must be monitored. |