Most oil spill tenders are decided on price, because the specification did not give the evaluation committee anything else to compare. This guide sets out the parameters that make bids genuinely comparable, and the omissions that let unsuitable equipment win.
Why oil spill TORs go wrong
Three failures account for most of it.
The specification describes equipment instead of duty. A TOR asking for “600 mm containment boom, 200 metres” tells a bidder nothing about where it will be deployed or what it must survive. Two compliant offers can then differ by a factor of three in tensile strength and still both be “600 mm boom”.
Performance is stated without a test basis. “Recovery rate 50 cubic metres per hour” is meaningless unless you say on what oil, at what thickness, and measured under which standard. Manufacturers quote peak throughput on ideal product. Real recovery on weathered crude off the Thai coast is a different number.
Nothing binds the parts into a system. Booms, skimmer, power pack, storage and towing arrangement have to work as one. Buying each on lowest price gives you a set of items that cannot be deployed together inside the response window.
The single most useful sentence you can add
“Bidders shall state all performance figures together with the test standard, oil type, oil viscosity and sea state under which they were obtained.”
This one requirement makes otherwise incomparable offers comparable, and quietly filters out bidders quoting brochure maxima.
Step 1: define the scenario before the equipment
Everything downstream depends on four decisions. Put them at the front of the TOR so every bidder designs to the same problem.
Water body
State whether the equipment will work in a sheltered harbour, a river, coastal water or offshore, with the expected wave height and current speed. This determines the boom class under ASTM F1523, and freeboard, draft, tensile strength and wave response all follow from it.
Design spill volume
State the tier and the volume in cubic metres you must contain and recover. This sets boom length, skimmer capacity and, critically, temporary storage volume.
Oil type
State crude, fuel oil, diesel or palm oil, with the expected viscosity range at local sea temperature. This decides the skimmer principle more than any other factor.
Response time
State the hours from alarm to on-scene and who deploys the equipment. This governs packing, reel and handling requirements, and whether a high-speed sweep system is justified.
State the current speed explicitly. Conventional booms begin losing oil to entrainment at roughly 0.7 knots of relative current across the boom, which is why sweep systems designed for higher speeds exist as a separate category.
Step 2: containment booms
- Boom class — specify by water body under ASTM F1523, not by a single height number. The common error is asking only for “600 mm boom”.
- Freeboard and draft — state both separately in millimetres, not overall height alone.
- Buoyancy-to-weight ratio — state a minimum and the method used to establish it. This is usually omitted, and it is what governs wave-following.
- Tensile strength — state the minimum breaking strength of the tension member in kilonewtons. This is the parameter that decides whether the boom survives a tow.
- Fabric — state base material, coating, weight in grams per square metre, and resistance to oil and UV. “PVC” with no weight or coating detail is not a specification.
- Connectors — state the type, such as ASTM slide or Unicon, and require compatibility with existing stock. New boom that cannot connect to the boom already in the store is a common and expensive outcome.
- Inflation — state self-inflating, air-inflated or solid flotation, with inflation time per 100 metres. This drives deployment manpower and time.
- Fire-resistant boom — if in scope, cite ASTM F2152 and state the exposure duration. Do not treat it as ordinary boom.
- Packing — state reel, container or bag, with dimensions and weight per section, before the equipment arrives and will not fit the vessel.
Step 3: skimmers
Skimmer selection follows the oil, not the budget. Specify the principle you need and require performance evidence on a stated test basis.
- Light, low viscosity, thin film — weir or disc oleophilic. Specify recovery rate and throughput efficiency, not just pump capacity.
- Medium viscosity crude — disc or drum oleophilic. Specify recovery rate at the stated viscosity, and oil recovery efficiency, which is the water content of what you recover.
- Heavy, weathered or emulsified — brush or grabber. Specify recovery rate on emulsion and the ability to pass debris.
- Debris-laden nearshore — brush with screening. Specify the maximum solid size passed without blockage.
Require figures to ASTM F631, the guide for collecting skimmer performance data in controlled environments. It yields recovery rate, throughput efficiency and oil recovery efficiency as three separate numbers. A skimmer with a high recovery rate and poor oil recovery efficiency is mostly pumping seawater into your storage, which is how a nominally adequate system runs out of tank space in the first hour.
Step 4: high-speed sweep systems
If the scenario includes open coastal water, or a requirement to cover distance quickly, conventional boom in a J or U configuration will not hold oil at useful tow speeds. Sweep systems such as the NOFI Current Buster are a distinct category and should be specified as such rather than treated as boom.
State encounter width in metres, maximum effective tow speed in knots, reservoir capacity in cubic metres, the number of vessels required to deploy, and deployment time from stowed to operational. Ask for the tow speed at which oil loss begins, not simply a maximum tow speed. Those are different claims.
Step 5: temporary storage, the part that gets forgotten
Recovered liquid has to go somewhere, and free water recovered with the oil consumes the same volume. If your skimmer runs at 50 cubic metres per hour with 50 per cent water content, you are filling storage at 50 cubic metres per hour regardless of how much of it is oil.
Specify total storage volume against the design spill and the intended operating period, the type of storage, transfer pump capacity and head, and the decanting arrangement. State explicitly whether decanting overboard is permitted under the operating authority’s rules. In many Thai port areas it is not, and that single point can double the storage requirement.
Step 6: what else belongs in the document
- Spares and consumables for a stated operating period, priced separately so they can be compared rather than hidden in the unit price.
- Training and commissioning, with the number of personnel, a deployment exercise on the buyer’s own water, and acceptance criteria for that exercise.
- Warranty and in-country support, with a stated response time for technical assistance.
- A spare parts availability commitment, typically ten years, and lead time for critical items.
- Compliance with the National Oil Spill Contingency Plan and the relevant port authority requirements, named explicitly.
- Factory acceptance and site acceptance tests, stating who witnesses each.
Standards worth citing
- ASTM F1523 — selection of booms in accordance with water body classifications, including minimum boom dimensions, buoyancy and tensile strength.
- ASTM F2683 — selection of booms for oil spill response.
- ASTM F631 — collecting skimmer performance data in controlled environments, covering recovery rate, throughput efficiency and oil recovery efficiency.
- ASTM F2152 — fire-resistant oil spill containment boom.
Cite the current edition, and state that equivalents will be accepted with evidence. A TOR that names a standard without allowing demonstrated equivalence can exclude capable suppliers on a technicality.
The five most common TOR mistakes
- Specifying boom by height alone, with no draft, buoyancy ratio or tensile strength.
- Accepting recovery rates with no test standard, oil type or viscosity attached.
- Sizing storage from the oil volume rather than the recovered liquid volume.
- Omitting connector compatibility, so new boom cannot join existing stock.
- Leaving a deployment exercise out of the acceptance criteria, so the equipment is proven on paper and never in the water until the day it matters.
A sample specification block
Adapt the numbers to your scenario. The structure is the point.
Containment boom, coastal, Tier 2. Boom shall be selected in accordance with ASTM F1523 for coastal water body classification, with a minimum freeboard of 300 mm and a minimum draft of 450 mm. Tension member minimum breaking strength shall be not less than 100 kN. Fabric shall be coated on both faces and resistant to the oils listed in Clause 2 and to UV exposure. Connectors shall be ASTM slide type and shall mate with the Owner’s existing stock. Bidders shall state freeboard, draft, buoyancy-to-weight ratio, tensile strength, fabric weight in grams per square metre and inflation time per 100 metres, together with the test basis for each figure.
Frequently asked questions
Should the TOR name a specific manufacturer?
Naming a product and adding “or equivalent” without defining what equivalence means invites disputes. Specify the performance parameters and the test basis instead, and let any supplier who can demonstrate them compete.
How much boom do we actually need?
It depends on the design spill and the deployment configuration rather than a rule of thumb. Containment around a berthed vessel, protection of a shoreline entrance and open water sweeping all give very different lengths for the same spill volume.
Can one skimmer cover every oil type?
No. Brush skimmers handle heavy and emulsified oil that a weir skimmer cannot, and a weir skimmer recovers thin light films faster than a brush. Where the risk profile spans both, specify interchangeable heads on a common power pack rather than one compromise unit.
Will SATU review a draft TOR before it goes to tender?
Yes. We regularly review draft specifications for Thai operators and port authorities, and comment on comparability and gaps before the document is issued.