Crashing a Barrage Project Programme Before the Monsoon
A barrage regulator project has four activities. Path 1 is A(7 weeks)–B(9 weeks)–D(6 weeks) = 22 weeks; Path 2 is A(7 weeks)–C(5 weeks)–D(6 weeks) = 18 weeks. Crashing data: A costs Rs 40,000 per week up to 2 weeks; B costs Rs 55,000 per week up to 3 weeks, but the crane is available for only 2 weeks of crashing; C costs Rs 20,000 per week up to 2 weeks; D costs Rs 90,000 per week up to 1 week. The monsoon window requires completion in 18 weeks. Liquidated damages are Rs 80,000 per week; site overheads are Rs 45,000 per week. The contractor has offered to compress the programme to 18 weeks if paid Rs 4 lakh. The engineer must decide the crash plan, compare it with the contractor's offer, and later assess a claim that the crane arrived late.
1. Identify the critical path, the float, and the cheapest crash plan to reach 18 weeks.
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Paths: A–B–D = 7 + 9 + 6 = 22 weeks; A–C–D = 7 + 5 + 6 = 18 weeks. The critical path is A–B–D and C has 4 weeks of total float.
To reach 18 weeks, crash only activities on A–B–D, cheapest first. A at Rs 40,000/week is cheapest; crash A by 2 weeks (its maximum) = Rs 80,000. B at Rs 55,000/week is next, but the crane limit is 2 weeks; crash B by 2 weeks = Rs 110,000. New duration = 22 − 4 = 18 weeks. D at Rs 90,000/week is not needed. Recheck the second path: with A reduced to 5, A–C–D = 5 + 5 + 6 = 16 weeks, so it does not become critical. Total crash cost = Rs 1.90 lakh.
2. Compare the crash cost with the contractor's offer and with the value of early completion.
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Benefit per week of earlier completion = liquidated damages avoided Rs 80,000 + site overhead saved Rs 45,000 = Rs 1.25 lakh per week. The crash plan costs Rs 1.90 lakh for 4 weeks, an average of Rs 47,500 per week, well below the benefit.
The contractor's offer of Rs 4 lakh for the same compression is more than twice the measured cost and should be rejected or negotiated down to the measured cost plus reasonable overhead. If the crane limit were relaxed, the next week of B would cost Rs 55,000, still below Rs 1.25 lakh, but only if a 17-week completion had further value. With no further LD saving, do not crash beyond 18 weeks.
3. The contractor later claims extra payment because the crane arrived late. How should the engineer assess the claim?
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Test the claim against the contract. If the crane was the contractor's own resource, the delay is its risk; if the employer supplied it, or the delay was due to a recorded site obstruction, a claim may lie. Ask for the crane mobilisation log, site diary, correspondence and revised programme.
The engineer should determine the actual critical delay caused, not the claimed amount, and grant an extension of time only if the delay was not the contractor's fault; costs follow only if the contract provides. Do not certify the crash payment as a variation without a written order.