Acceleration is the process by which a contractor compresses its programme — typically by deploying additional resources, working overtime or re-sequencing the works — in order to recover time lost or to achieve completion earlier than would otherwise be possible. Core Principle 16 of the SCL Delay and Disruption Protocol distinguishes between directed acceleration and constructive acceleration.
Directed acceleration occurs where the employer or the engineer expressly instructs the contractor to accelerate, typically through a variation instruction. The contractual basis is clear, and the contractor's entitlement to the cost of acceleration follows the variation valuation provisions of the contract.
Constructive acceleration is more contentious. It arises where the contractor, faced with a delay event for which it considers itself entitled to an EOT, is denied that EOT (either expressly or by silence) and accelerates in order to avoid liability for liquidated damages. The contractor then claims the cost of acceleration on the basis that, but for the wrongful denial of the EOT, the acceleration would not have been necessary.
Constructive acceleration claims are challenging. They typically require the contractor to prove that an EOT was due and was wrongly refused, that the contractor accelerated in response, that the acceleration measures were reasonable and reasonably costed, and that the contractor gave notice of its intention to accelerate. In some jurisdictions, constructive acceleration is not recognised at all; in others, it is recognised only on restrictive terms.
In the Middle East, constructive acceleration claims are relatively rare but increasingly seen on programmes where time-related liquidated damages are punitive. Tribunals have generally required strong evidence of the wrongful refusal of EOT, of the contractor's protest, and of the actual cost of acceleration measures.
A delay expert witness instructed on an acceleration claim must be able to demonstrate, by reference to a proper delay analysis, what EOT was due at the time of the alleged constructive instruction. A quantum expert will then value the cost of the acceleration measures actually taken. The two analyses must align: an acceleration claim with no underlying delay entitlement will fail, as will an acceleration claim without proper substantiation of cost.