Chittenden: Pricing the Dive Schedule

A dive needs an inspector as well as a crew

The July 2025 tender for the Chittenden Small Lock emergency closure system ties underwater access to a government diving inspector. It requires seven calendar days of written notice for each dive and at least two work days of notice to cancel or reschedule. A late cancellation can produce daily deductions from the contractor's pay. Diving itself receives no separate measurement or payment. Together, these clauses make the reliability of the dive schedule part of the price of the work. ^[1]

USACE awarded the emergency closure system to Redside Construction on 23 September 2025. The award notice records $4,457,500 for the base and all options. The work includes a new crane, a steel bulkhead, storage arrangements and bearing plates in the existing concrete lock wall. An August 2026 navigation notice schedules underwater installation of stop-log inserts from 7 December 2026 to 18 January 2027. [1-3]

The contractor's estimate has to carry the accepted dive method, an available inspection arrangement, the crane and crew configuration, and the consequences of moving a booked dive. Those dependencies are visible in the published tender before anyone assigns a daily production rate.

Put both notice periods into the work programme

Section 01 35 50 requires the contractor to notify the designated dive coordinator and contracting officer in writing at least seven calendar days before each scheduled dive. Failure to give that notice can delay work when an on-site inspector is unavailable; the clause assigns that particular delay exposure to the contractor. Diving requires an inspector on site unless the coordinator permits off-site monitoring after an initial on-site inspection. ^[1]

Cancellation uses a different clock. Notice must reach the government during normal business hours at least two work days before the first scheduled dive day. If that notice is late, the contractor becomes liable for the inspector's daily rate from cancellation until the dive commences. A partial day counts as a full day. Each cancellation is limited to seven charged days, while each further cancellation or rescheduling is treated as a new dive for scheduling and cost purposes. The stated minimum deduction is $1,000 per day. ^[1]

Record the scheduled dive, the seven-calendar-day notice date and the cancellation cutoff as separate entries. The cutoff needs the applicable working calendar and business hours. A programme entry saying "diving next week" gives the commercial team too little information to decide whether a change can still be made within the notice period.

The seven-day cap applies to each event

The table applies the clause's $1,000 minimum daily rate to assumed delay-day counts after a late cancellation. Each event's counted days are capped at seven. These are estimating examples; the inputs describe chargeable intervals, with any partial day already counted as a whole day.

The cap is expressed in days. A higher inspector daily rate increases the cash deduction, and a second cancellation creates another event. The contractor therefore needs an event-by-event allowance, alongside the costs of keeping or rebooking the dive spread. A timely cancellation removes this clause's late-notice trigger; crew standby, plant hire and another mobilisation still depend on the contractor's supply agreements.

This is a specific cost mechanism inside a lump-sum tender. Pricing only expected hours in the water leaves document preparation, inspection coordination and interrupted mobilisation outside the production estimate. A low allowance for those activities is consumed when the sequence changes, even if the underwater task's measured quantity stays the same.

IMWO original diagram based on USACE Section 01 35 50, Amendment R0002, 11 July 2025

The work method has to support the booking

Amendment R0002, issued on 11 July 2025, added the diving section in response to a question about installing the recess bearing plates wet or dry. The base pricing section includes cofferdam design and fabrication for dry access within the bearing-plate item, CLIN 0005. The anchor specification revised under R0003 on 15 July still requires water to be removed from holes before adhesive is introduced, with the concrete kept within the adhesive manufacturer's temperature limits through curing. Both amendments preceded the 23 July offer deadline. [1, 4, 5]

An underwater access plan has to show how those installation conditions will be achieved. Resolve the enclosure, pumping and hole-preparation method with the plate alignment and anchoring sequence before fixing the dive date. The approved diving arrangements and the anchor installation conditions belong on the same method submission. Adding a diving crew to the programme leaves that technical question open until the proposed method addresses it.

The diving section requires surface-supplied air, accepted personnel and equipment records, a site-specific operations plan, an activity hazard analysis and emergency arrangements. Changes to the mission, depth, personnel or equipment require review and acceptance before operation. When a crane is used, its certified operator must be dedicated to crane operations and separate from the dive team. These are resources and preparation activities to include in the work-item estimate. ^[1]

Make rescheduling a recorded commercial decision

IMWO recommends a short readiness record for each planned dive: the accepted task and method revision; the crane and dive-team configuration; the inspection arrangement; proof of the seven-day written notice; and the cancellation cutoff. The site lead should confirm those dependencies with the planner before the cutoff. If a plate, anchor detail or access arrangement is unresolved, the commercial team can then compare an orderly rebooking with the cost of holding the spread and exposing the job to late-notice deductions.

Keep the notification evidence with the daily dive logs and the cost record. For every changed booking, record who requested the change, when notice reached the government, the inspector arrangement, the counted days and any deduction actually assessed. That gives the contractor a traceable account of the interruption and gives the owner a way to distinguish incomplete preparation from a change arising during the work. The deduction clause supplies the trigger; the contemporaneous record establishes what happened.