Fuel (Bunker) for Shipowners’ Account in a Time Charterparty
Bunker (Fuel) allocation under a time charterparty is not decided only by who bought the fuel. It is decided by the purpose for which the fuel was consumed, the period during which it was consumed, the wording of the charterparty, and the evidence available to support the calculation. Although the usual time charter arrangement places commercial fuel consumption on the charterer, several important categories of consumption may properly fall on the shipowner.
In a conventional time charter, the shipowner provides the ship, master, officers, crew, technical management, maintenance, insurance, stores, and the basic nautical service of the ship. The charterer receives the commercial use of the ship and normally pays hire, bunkers, port expenses, canal charges, towage, pilotage, agency, and voyage-related costs. This division is commercially logical because the charterer chooses the ship’s employment and therefore controls much of the fuel exposure.
However, that principle is not absolute. Fuel may be consumed while the ship is off hire, undergoing owners’ repairs, deviating for an owners’ purpose, producing domestic services for the crew, conducting machinery tests, waiting for class attendance, or performing work that is not part of the charterer’s commercial employment. In such circumstances, the charterparty may require the shipowner to reimburse the charterer, credit the hire account, supply replacement bunkers, or apply another agreed accounting method.
The central question is therefore economic responsibility, not physical ownership. The charterer may own the bunkers in the tanks, yet the shipowner may have to bear the cost of specific quantities consumed for owners’ purposes. Conversely, the shipowner may remain in technical control of the machinery, but the charterer may still bear fuel used for the ordinary commercial employment of the ship.
The Basic Time Charter Allocation
At delivery under many time charters, the charterer purchases the bunkers remaining on board from the shipowner at an agreed price or by an agreed valuation formula. During the charter period, the charterer arranges and pays for further bunker stems. At redelivery, the shipowner normally buys back the remaining bunkers from the charterer at the contractual redelivery price or another agreed basis.
This structure gives the charterer a strong financial reason to manage speed, routing, trading pattern, bunker stems, fuel grades, and redelivery quantities carefully. The charterer bears the ordinary energy cost of moving the ship in the charterer’s service. The charterer also usually bears the cost of fuel used for cargo operations where those operations are part of the chartered employment.
The shipowner, however, does not hand over technical control merely because the charterer buys the fuel. The shipowner and master remain responsible for navigation, safety, machinery operation, maintenance, crew management, and the efficient working of the ship. Where fuel is consumed because the ship is defective, unavailable, being repaired for owners’ account, or being used for crew domestic purposes, the commercial basis for charging that fuel to the charterer becomes weaker.
A properly drafted bunker clause should therefore work together with the off-hire clause, speed and consumption warranty, dry-docking clause, deviation clause, domestic consumption clause, cargo-operation clauses, and environmental cost provisions. If those clauses are inconsistent, bunker disputes may arise even where the quantities themselves are not controversial.
Meaning of Bunkers for Shipowners’ Account
The phrase “bunkers for shipowners’ account” does not usually require the shipowner to arrange a separate physical supply of fuel at the moment of consumption. In practical terms, the ship continues to burn whatever fuel is in its tanks. The account between the parties is corrected later by credit, reimbursement, deduction, replacement, or final statement adjustment.
The accounting method may take several forms. The charterer may deduct the value from the next hire payment. The shipowner may reimburse the charterer separately. The quantity may be removed from the charterer’s consumption account. The amount may be included in the final hire reconciliation. The shipowner may physically replace the quantity used. The parties may also agree a fixed daily allowance for minor categories of owners’ consumption.
The valuation method matters. A clause may use the charterer’s actual purchase price, the weighted average cost of fuel on board, the delivery or redelivery bunker price in the charterparty, the market price at the place and time of consumption, the cost of replacement at the next bunkering port, or a published index. During volatile bunker markets, these methods can produce very different results.
Clear drafting should identify both the quantity mechanism and the price mechanism. A clause that says only that owners shall pay for fuel consumed for owners’ account may still leave the parties arguing over whether value is based on actual cost, replacement cost, contractual price, or market price.
Fuel Consumed During Off-Hire Periods Under Time Charter
The most familiar category of owners’ bunker consumption is fuel burned while the ship is validly off hire. A time charter normally keeps hire running from delivery until redelivery unless the charterer proves that the circumstances fall within the off-hire clause. Once the ship is properly off hire, many forms and rider clauses also place fuel consumed during that period on the shipowner’s account.
Off-hire events may include machinery breakdown, main engine failure, auxiliary engine failure, hull or equipment defect, insufficiency of crew, detention caused by ship documents or ship condition, grounding caused by a ship-related problem, time lost during repairs, scheduled dry-docking where the clause provides for off-hire, failure of cargo gear, or deviation for an owners’ cause. The actual wording remains decisive. A technical problem does not automatically stop hire unless the clause is triggered.
Where the charterparty states that all bunkers consumed while off hire are for shipowners’ account, the claim may include fuel used by main engines, auxiliary engines, boilers, generators, inert systems, pumps, incinerators, heating systems, cooling systems, and other machinery during the qualifying off-hire period. If the wording refers only to extra bunkers or bunkers consumed because of the event, the calculation may be narrower.
The parties should identify the exact start and end of the off-hire period. A breakdown may begin at sea, but repairs may continue in port. The ship may resume limited service before full efficiency is restored. Sea trials may be required before the ship is again commercially usable. Each phase may require a different treatment depending on the clause.
Off-Hire Fuel and Excess Performance Fuel Under Time Charter
Off-hire bunker consumption and excess consumption under a performance claim are different claims. They may arise from the same factual background, but they do not follow the same legal or accounting route.
An off-hire bunker claim concerns fuel used during a period when the charterer is not required to pay hire, or during a period that the clause treats as owners’ time. The claim is period-based. The question is whether the ship was off hire and what fuel was consumed during that period.
A speed and consumption claim concerns the difference between warranted performance and actual performance. The ship may remain on hire throughout the voyage, but if it fails to achieve the promised speed or consumes more than warranted in qualifying conditions, the charterer may claim the additional time and additional fuel caused by underperformance.
The difference matters because the same fuel should not be recovered twice. If all fuel during three off-hire days has already been credited to the charterer, the charterer should not also include that same quantity in a separate excess-consumption claim. Equally, a shipowner should not reject a properly framed performance claim merely because the ship was never off hire.
Fuel (Bunker) Used for Shipowners’ Purposes While the Ship Remains on Hire Under Time Charter
Not every owners’ bunker claim depends on off-hire. Some fuel may be consumed for an operation undertaken primarily for the shipowner’s benefit even while the charterparty does not suspend hire. The allocation depends on the wording and the commercial purpose of the activity.
Examples may include class inspections, statutory surveys, owners’ underwater inspections, machinery testing, maintenance not connected with the charterer’s employment, deviation to obtain spare parts, deviation to land technical personnel, crew change beyond the agreed route, landing a sick or injured crew member where the cause is not attributable to the charterer, or gas-freeing required for owners’ repair work.
Some operations may benefit both parties. A repair may restore the ship’s efficiency for the charterer but also preserve the shipowner’s asset. A deviation may be necessary for safety. A crew change may be permitted under the charter without loss of hire if it does not delay the ship. For this reason, the clause should not rely only on general commercial impression. It should state whether hire continues, whether extra time is credited, and who bears the fuel.
If the ship makes distance toward the charterer’s destination during an owners’ operation, an allowance may be required. The charterer should not be charged with fuel consumed solely for owners’ purposes, but the charterer should also not receive a windfall for fuel that would have been consumed in any event to advance the voyage. A fair calculation may compare the actual route with the route that would have been followed without the owners’ operation.
Domestic Consumption for the Master, Officers, and Crew
Many time charterparties recognise that some fuel is consumed not for commercial employment but for maintaining the persons living and working on board. This is usually called domestic consumption. The commercial logic is simple: the charterer pays for the energy used to employ the ship, while the shipowner bears the cost of feeding, accommodating, and maintaining the crew.
Domestic energy may be used for cooking, accommodation heating, air conditioning, mechanical ventilation, lighting, refrigeration of crew provisions, laundry, hot water, sanitary services, fresh-water production for crew use, communication equipment, computers, televisions, personal appliances, and ordinary hotel services required on board.
Older clauses often refer to traditional equipment such as stoves, grates, heating arrangements, or water condensers. Modern ships rarely fit those categories neatly. Galley equipment may be electric. Accommodation air conditioning may be supplied through auxiliary engines. Fresh water may be produced by evaporators or reverse-osmosis units. A single generator may power navigation equipment, cargo equipment, engine-room systems, accommodation lighting, refrigeration, and crew domestic services at the same time.
This creates a measurement issue. Without a dedicated meter or agreed allowance, it may be difficult to prove how much generator fuel was used for domestic purposes rather than cargo work, navigation equipment, machinery support, or ship safety systems. A fixed daily domestic allowance is often the simplest way to avoid disproportionate disputes.
Broad and Narrow Views of Domestic Fuel (Bunker)
Domestic-consumption wording may be read broadly or narrowly. A broad reading treats the clause as expressing a practical commercial principle: fuel for propulsion and cargo employment is for the charterer, while fuel for the crew’s ordinary living requirements is for the shipowner. Under this approach, modern equivalents of heating, cooking, lighting, and accommodation services may be included even if old wording does not list them one by one.
A narrower reading confines the allowance to the services expressly named in the clause. If the clause mentions cooking and accommodation heating only, the charterer may argue that air conditioning, ventilation, laundry, or general electrical hotel load is outside the allowance. If the clause refers only to fuel used in a particular stove or heater, electric domestic services may become contentious.
The safer solution is to draft the clause in modern language. If the parties intend all ordinary accommodation and crew domestic energy to be for shipowners’ account, the clause should say so. If they intend only a limited daily allowance, that allowance should be stated clearly by quantity, fuel grade, and valuation method.
Galley Fuel and Cooking
Fuel or energy used for cooking is traditionally treated as an owners’ expense because feeding the crew is part of the shipowner’s crewing obligation. The difficulty is rarely the principle; it is the proof of quantity.
Some ships use electric galley equipment. Some use steam, marine gas oil, or another fuel source. Where the galley is supplied through the ship’s general electrical system, consumption cannot always be isolated from other auxiliary loads. Over a short voyage, the amount may be minor. Over a one-year or multi-year charter, the accumulated allowance may become commercially significant.
A charterparty can avoid argument by stating a fixed daily quantity, a fixed daily monetary allowance, a percentage of auxiliary-engine consumption, a combined domestic-consumption allowance, or a metered method where the ship’s equipment permits. Without such wording, a later estimate may be challenged as uncertain or speculative.
Fresh-Water (FW) Production
Traditional bunker clauses may also place fuel used for condensing or producing fresh water for the crew on the shipowner’s account. Modern ships may produce fresh water through evaporators, reverse-osmosis plants, or other machinery, and the energy required may be part of the auxiliary load.
The clause should distinguish between water used by the crew for drinking, cooking, washing, and sanitary services, water required for machinery or boilers, water used for deck washing, water used for cargo holds or tanks, and water required for cargo operations. Crew domestic water is normally connected with the shipowner’s obligations. Cargo-related water may belong to the charterer’s commercial employment, depending on the charterparty.
If one plant serves multiple purposes, the parties should agree a fair allocation. That allocation may be based on daily allowance, production logs, tank records, operating hours, or a technical estimate. The method should be agreed before the dispute arises, not reconstructed after several months of operation.
Heating, Air Conditioning, and Ventilation
Accommodation climate control is one of the most difficult areas in older bunker clauses. Heating may be mentioned expressly, but cooling and ventilation may not be. Modern crew accommodation often depends on compressors, pumps, fans, cooling-water systems, and electrical generation rather than an easily identifiable fuel line.
A modern domestic-consumption clause should state whether owners’ account includes accommodation heating, accommodation air conditioning, mechanical ventilation, bridge and control-room climate control, cooling for electronic equipment, laundry ventilation, and air conditioning while the ship is idle in port.
Not every cooling load is domestic. Air conditioning for cabins is different from cooling required for engine-control systems, cargo-control rooms, refrigerated cargo, or sensitive cargo equipment. Mixed systems should be handled through meters, technical allocation, or an agreed percentage.
Fuel (Bunker) Used for Cargo Operations Under Time Charter
Fuel used for cargo operations is usually connected with the charterer’s employment of the ship and is therefore normally for charterer’s account while the ship is on hire. This may include energy used by cargo cranes, winches, grabs, cargo pumps, tank-cleaning machinery, inert gas systems, cargo heating, cargo refrigeration, hold ventilation, ballast systems required for cargo work, hatch-cover machinery, deck lighting during cargo operations, and other cargo-related equipment.
The purpose of the operation is more important than the name of the equipment. A pump used for cargo discharge may be for charterer’s account. The same or similar machinery used for owners’ repairs, testing, cleaning after an owners’ defect, or class requirements may be for shipowners’ account. If cargo work is prolonged because ship’s equipment fails, the charterer may also have a separate claim for lost time and additional bunkers.
Records should identify when cargo equipment ran, why it ran, who ordered the operation, and whether the time was part of ordinary cargo work or a consequence of a ship-related problem. Without these records, later bunker allocations can become highly uncertain.
Bunkers During Repairs and Dry-Docking Under Time Charter
A ship may consume considerable fuel during repairs and dry-docking. It may run generators, boilers, pumps, compressors, lighting, accommodation systems, and machinery tests. It may shift between berths, proceed to a repair port, return from dry dock, or carry out sea trials. These quantities should not be treated casually.
The charterparty should state whether the ship is off hire during scheduled dry-docking, emergency repairs, maintenance alongside, underwater inspection, or sea trials. It should also state whether the deviation to and from the repair location is owners’ time, whether bunkers are for owners’ account, whether any distance made good is credited, and how remaining bunkers are measured before and after the repair period.
Repairs caused by charterers’ breach require separate analysis. If damage results from unsafe port nomination, dangerous cargo, stevedore damage for which charterers are responsible, bad fuel supplied by charterers, or unlawful employment orders, the shipowner may recover time, bunkers, repairs, and expenses from charterers even if the immediate repair period appears to be owners’ work. The ultimate allocation should follow causation and the charterparty.
Bunkers During Deviation Under Time Charter
Deviation can occur for repairs, medical assistance, crew matters, rescue, safety, bunkering, weather avoidance, port closure, or a charterer’s revised orders. The fuel treatment depends on cause, necessity, charter wording, and whether the deviation served the charterer’s employment or the shipowner’s own purpose.
A deviation ordered by the charterer will usually remain for charterer’s account. A deviation made for owners’ repairs or owners’ stores may be for shipowners’ account. A safety deviation may require closer examination. Medical assistance for crew may be treated differently from a deviation required by charterer’s cargo or port arrangements.
The calculation should normally consider the point of departure from the intended route, the point where the ship resumed the charter service, extra sea distance, port consumption, fuel consumed while waiting, distance made good toward the destination, and fuel that would have been consumed on the contractual route. Unless the clause says otherwise, the correct claim may be for additional fuel caused by the deviation rather than every tonne burned during the calendar period.
Emergency Bunker (Fuel), Salvage, and General Average
Fuel consumed during an emergency may raise several separate issues. The ship may burn additional bunkers while fighting a fire, refloating after grounding, entering a port of refuge, operating emergency pumps, assisting another ship, or conducting temporary repairs. The charterparty may allocate some of this consumption to the shipowner, while a general average adjustment may later consider whether the expenditure was incurred for the common safety.
Charterparty bunker allocation and general average contribution are not the same question. A bunker credit under the charterparty does not automatically determine the final contribution between ship, cargo, bunkers, and freight interests. Equally, a general average allowance does not automatically decide whether the ship was off hire or whether the charterer must pay hire during the emergency.
The parties should preserve complete bunker records and ensure that the same fuel cost is not recovered twice. Emergency consumption should be separated from ordinary consumption, off-hire fuel, domestic allowance, cargo-operation fuel, and any later general average or insurance recovery.
Bunker (Fuel) Quality and Shipowners’ Account Consumption
Although the charterer normally supplies bunkers under a time charter, the shipowner and master remain responsible for safe handling and use of fuel on board. The charterer must supply fuel meeting the contractual specification. The shipowner must store, segregate, treat, purify, heat, test, and consume fuel properly in accordance with good marine practice and the ship’s technical limits.
If fuel is contaminated, unstable, incompatible, or otherwise off specification, the ship may lose time and burn additional bunkers during segregation, testing, tank cleaning, debunkering, replacement, machinery flushing, or repairs. Responsibility depends on cause. If the charterer supplied non-compliant fuel, the charterer may bear the consequences. If the shipowner mismanaged compliant fuel, mixed it improperly, failed to follow procedures, or unreasonably rejected usable fuel, the shipowner may bear the loss.
A ship may be off hire during part of a fuel-related incident, but that does not end the analysis. The party whose breach caused the incident may ultimately have to reimburse the other. The bunker account, off-hire account, damage claim, and fuel-quality claim should therefore be reconciled together.
Valuing Bunkers (Fuel) for Reimbursement
Once the parties agree that a quantity of fuel is for shipowners’ account, the next question is value. This is often more difficult than expected because the physical bunkers in the tank may have been purchased in several stems at different prices and may not be replaced until later at another port.
Possible valuation methods include the actual invoice price paid by the charterer, the weighted average price of fuel on board, the most recent stem price, the delivery bunker price, the redelivery bunker price, the market price at the time of consumption, the market price at the place of replacement, a published bunker index, or the actual cost of the next replacement stem.
The clause should also state whether valuation includes barge charges, delivery fees, port dues, taxes, testing costs, sampling expenses, brokerage, currency conversion, fuel-quality premiums, regulatory charges, and physical delivery losses. A narrow price clause may exclude costs that the charterer actually incurred. A broad replacement-cost clause may require more evidence but may better reflect the real economic loss.
Measuring the Bunker Quantity Consumed Under Time Charter
The party claiming a bunker credit must prove the quantity with reasonable reliability. The best evidence is normally contemporaneous shipboard data supported by tank records, operating logs, and event reports.
Relevant evidence may include daily engine-room reports, noon reports, arrival and departure reports, tank soundings, flow-meter records, main engine load data, generator running hours, boiler records, incinerator logs, bunker delivery notes, fuel-transfer records, laboratory analysis, density data, repair logs, fresh-water production records, cargo-equipment running hours, and off-hire event reports.
The shipowner controls much of this evidence through the master and chief engineer. The charterer should request timely records when a claim is likely. The shipowner should maintain credible records because unsupported refusal of a reasonable bunker claim may damage the working relationship and create a wider hire dispute.
Where exact measurement is impossible, the parties may use an agreed daily allowance or a technical estimate. The estimate should reflect the actual ship, machinery, season, operating mode, and trading pattern. A standard figure copied from another ship may be unsuitable.
Avoiding Double Counting in Bunker Accounts
Bunker accounts often overlap with hire deductions, speed claims, off-hire claims, deviation claims, repair claims, and damage claims. Double counting can occur easily unless each quantity is placed under one contractual heading.
The final reconciliation should separate ordinary on-hire consumption, owners’ domestic allowance, total off-hire consumption, extra consumption caused by underperformance, fuel consumed during owners’ deviation, fuel used for repairs and testing, cargo-operation fuel, fuel saved because the ship did not perform a voyage, distance made good, and amounts already credited in earlier statements.
Each tonne should appear once, under the correct legal and accounting basis. A well-presented bunker statement should explain the period, event, clause relied upon, quantity, fuel grade, price, credit already given, and balance claimed. This makes settlement easier and reduces the risk of payment default arising from disputed deductions.
Environmental Costs and Alternative Fuels
Modern bunker accounting is no longer limited to conventional fuel price. Ships may use very low sulphur fuel oil, marine gas oil, biofuel blends, LNG, methanol, shore power, or other energy sources. Energy consumption may also create emissions allowances, greenhouse-gas intensity consequences, carbon charges, pooling adjustments, or other regulatory costs.
The fact that physical bunkers are for shipowners’ account does not automatically decide who bears every environmental cost linked to that consumption. Separate clauses may allocate emissions allowances, data reporting, carbon-intensity compliance, fuel-intensity penalties, alternative-fuel premiums, and regulatory adjustments.
A modern charterparty should state whether energy consumed during off-hire is excluded from the charterer’s emissions liability, whether owners’ domestic consumption is counted in the charterer’s regulatory account, and how alternative fuels are valued when consumed for owners’ purposes. Without coordinated wording, the charterer may receive credit for the fuel itself but still face a related environmental charge.
Drafting a Modern Shipowners’ Bunker Clause
A strong owners’ bunker clause should avoid relying only on outdated wording designed for older ship machinery. It should state the commercial principle and then provide a workable measurement and valuation system.
The clause should address all bunkers consumed during agreed off-hire periods; fuel used for owners’ repairs, maintenance, surveys, dry-docking, deviations, sea trials, and testing; domestic services for the master, officers, and crew; cooking, heating, cooling, ventilation, laundry, refrigeration of provisions, hot water, sanitation, and fresh-water production; mixed electrical loads; auxiliary-engine consumption; cargo-equipment treatment; fuel grades; evidence requirements; daily allowances; valuation price; timing of credit; distance made good; environmental costs; disputed periods; and preservation of claims where one party’s breach caused the consumption.
For minor domestic consumption, a fixed daily allowance may be commercially efficient. For substantial off-hire events, actual measurement should be required. For deviations and repairs, the clause should explain whether the credit covers total fuel consumed or only the additional fuel caused by the owners’ operation.
Practical Example of Shipowners’ Bunker Credit
A bulk carrier is employed under a one-year time charter. The charterer purchases the bunkers at delivery and supplies all further stems. The charterparty states that all bunkers consumed while off hire are for shipowners’ account and also provides a fixed daily allowance for crew domestic consumption, including cooking, accommodation heating and cooling, laundry, and crew fresh-water production.
During the charter, an auxiliary-engine failure places the ship off hire for three days while repairs are completed. During those three days, the ship consumes marine gas oil for generators, accommodation services, pumps, lighting, repair testing, and ordinary domestic services. Because the clause places all off-hire fuel on shipowners’ account, the shipowner credits the full properly proven quantity consumed during the three-day off-hire period.
The charterer also claims the fixed domestic allowance for the whole charter period. To avoid duplication, the allowance for the three off-hire days should not be added again if the full fuel consumption for those days has already been credited. The parties value the quantities under the replacement-cost formula in the charterparty and include the balance in the next hire statement.
Practical Recommendations for Shipowners
Shipowners should review bunker clauses before fixing and ensure that domestic allowances match the ship’s actual equipment. They should maintain accurate fuel records, separate consumption categories where technically possible, coordinate repair and deviation clauses with bunker wording, and make sure that off-hire calculations do not conflict with speed and performance claims.
Shipowners should challenge unsupported estimates, but they should not reject a fair claim merely because the ship lacks dedicated sub-metering. They should preserve records showing generator loads, machinery operation, repair periods, and event timing. Where charterers’ fuel, cargo, contractors, or orders caused the consumption, shipowners should reserve recourse rights expressly.
Shipowners should also update older clauses for alternative fuels and environmental charges. A clause that works for conventional fuel oil may not be sufficient for biofuel blends, LNG, methanol, shore power, or emissions-linked costs.
Practical Recommendations for Charterers
Charterers should negotiate a clear daily allowance or measurement formula for domestic consumption before the fixture is concluded. They should expressly include air conditioning, ventilation, electrical hotel loads, fresh-water production, refrigeration of provisions, laundry, and other accommodation services where those items are intended to be for shipowners’ account.
During off-hire events, charterers should obtain daily consumption records, tank soundings, engine-room logs, repair reports, and event timelines. Each deduction in the hire statement should identify the contractual clause, quantity, fuel grade, price basis, and calculation period. Speculative bunker deductions can create avoidable payment disputes and may expose the charterer to default consequences.
Charterers should distinguish total off-hire fuel from excess consumption under a performance claim. They should also ensure that valuation clauses cover delivery charges, taxes, testing costs, and environmental charges where those items are intended to be recoverable. Where bunker quality or contamination is involved, charterers should notify insurers and preserve claims against suppliers.
Conclusion
The ordinary time-charter bargain places commercial bunker consumption on the charterer, but that bargain does not make the charterer responsible for every tonne consumed during the charter period. Fuel used while the ship is off hire, for owners’ repairs, for owners’ deviations, or for agreed crew domestic services may properly be for shipowners’ account.
The most common disputes arise from old wording, mixed electrical loads, accommodation air conditioning, fresh-water production, owners’ repair periods, deviations, sea trials, fuel valuation, and overlap between bunker credits and other claims. These problems are made worse when the ship’s records do not separate consumption by purpose or event.
A professionally drafted time charterparty should define owners’ bunker categories, state how quantities will be measured, identify the price used for reimbursement, prevent double counting, and coordinate bunker provisions with off-hire, performance, deviation, repair, general average, and environmental clauses.
Clear bunker allocation protects both sides. The charterer pays for fuel used to employ the ship commercially. The shipowner bears the fuel cost connected with ownership, technical unavailability, crew domestic services, and activities undertaken for the shipowner’s own account. When the wording, records, and accounting method are disciplined, bunker claims become a manageable part of time-charter performance rather than a source of unnecessary dispute.