Engineering

Ardrossan: Designing Passenger Access Around the Fleet

Published 31 October 2026 Publisher IMWO Section Engineering
Conceptual Ardrossan passenger-access envelope with three illustrative door positions and vertical tidal travel. Positions are not measured vessel dimensions.

IMWO original engineering diagram; source: Caledonian Maritime Assets Ltd

A ferry berth can fit the ship and still deliver a poor boarding route. Ardrossan's new design materials show how door positions, berthing orientation and tide range shape the choice between a hoistable gangway and a passenger access system.

In this article

The passenger door sets the design envelope

Passenger access at Ardrossan has to reach a moving target. The target changes vertically with tide and vessel loading, and along the berth with the ship and its orientation. Choosing an access system before defining that range can lock the civil design to a narrow set of vessel calls.

CMAL's autumn engagement boards, published on 30 October, place a hoistable gangway and a powered Passenger Access System, or PAS, alongside one another. The boards say passenger-door positions vary across the major vessels expected at Ardrossan and change when ships berth bow-in or stern-in. The proposed PAS must cover that fleet and tidal envelope. [1,2]

The choice affects the terminal's operating resilience. A replacement ferry may have adequate length, beam and vehicle-ramp compatibility yet put its passenger door outside a fixed access arrangement. An otherwise usable substitute then brings a boarding restriction, a different route or additional handling. Fleet compatibility therefore belongs in the access-system requirement before the berth and terminal connections are frozen.

Berthing orientation moves the terminal connection

The design remains in development. CMAL identifies the previous arrangement as a starting point and presents a north-south berth option tested by CalMac Masters in a simulator in July 2026. The boards anticipate linkspan replacement, partial wall demolition or repair, dredging, new berth infrastructure and associated services. [1,3]

Simulator assessment and passenger access address connected parts of the same operation. A preferred manoeuvre can change which side or end of a vessel faces the terminal. That changes the position the access equipment must reach and the passenger route across the quay. The door schedule should therefore travel with each berth-orientation option through design review.

Design inputEffect on passenger accessConsequence for the civil package
Vessel and door locationRequired along-berth reach and landing positionEquipment location, foundations and clear working envelope
Tide and loaded conditionVertical travel, gangway angle and landing movementConnection levels and operating limits
Bow-in or stern-in callDifferent door position relative to the terminalPassenger route, barriers and vehicle separation
Substitute vesselAdditional door and operating combinationsReserved reach and adaptable terminal connection

The matrix is an IMWO design-review method drawn from the operating variables in the boards. It should contain the intended fleet and credible substitutions, with each operating combination signed off by the ferry operator. Dimensions and movement allowances can then be issued to both the access supplier and civil designer from one controlled schedule.

A simpler gangway carries an operating trade

CMAL describes the hoistable gangway as the simpler, lower-cost option. Its comparison identifies longer boarding from a comparable starting point, a more exposed journey and particular difficulties with luggage, pets and reduced mobility. Gangway angles and a slatted deck are among the practical concerns; a covered arrangement remains a possible development. [1]

Those effects accumulate through a sailing schedule. A slower boarding route consumes time during each call, while weather and passenger mix make that time variable. The relevant comparison is the cost of providing and maintaining the access arrangement alongside the operating time and assistance it needs. A capital-cost comparison alone leaves the ferry operation outside the decision.

A PAS uses powered movement to accommodate vessel positions and tide. CMAL associates it with better shelter and passenger comfort, greater complexity and a higher cost; serving a wider fleet adds engineering demand. [1] The mechanism, controls, emergency arrangements and maintenance access become part of the reliability requirement. A highly adaptable machine still needs a workable passenger route during a fault or planned outage.

The procurement needs observable boarding tests

The design brief should state the required vessel-door combinations and the operating conditions for each. Tenderers can then show achievable reach, landing geometry, gradients and clearances across the same envelope. Where a combination needs an operating restriction, the ferry operator should assess its effect on substitutions and the sailing plan before accepting the design.

Commissioning should include representative boarding trials with luggage and mobility aids, alongside the mechanical and control tests specified for the equipment. Record the route length, assistance required, obstructions and transfer sequence at the operating extremes. Those observations turn a general promise of accessible boarding into a design result the operator can inspect.

The civil and equipment packages also need an agreed dimensional handover. Surveyed foundation positions, connection levels and the protected movement zone should be accepted before the supplier finalises installation. A late foundation change can move the access range relative to every vessel door. Allowing the equipment supplier to comment while the berth layout remains adjustable costs design effort early and protects against that larger rework later.

The access choice precedes the construction date

The boards set out outline design, an Outline Business Case, detailed design and procurement, followed by a Final Business Case and construction. They describe roughly 12-14 months of pre-construction activity, depending on consents, and an expected 24-36 months of construction depending on scope. [1] These are stage allowances, so programme review should track the decision and consent needed to release each stage.

October's essential maintenance and the return of ferry operations are a separate asset-management task from this redevelopment. CMAL's 8 October account covers that return; the current redevelopment page and FAQ describe the longer-term scheme. [3-5] The passenger-access decision belongs to the new layout and its future fleet requirement.

For Ardrossan, the next design output should be a vessel-door and orientation schedule agreed with the operator, followed by a whole-life comparison of the gangway and PAS against it. That sequence gives cost advisers a defined operating requirement to price and gives the civil designer the geometry needed for the terminal connection. It also makes the consequence of excluding a vessel combination visible before procurement.

Subject index

Related subjects

These subject pages bring together related projects, technical articles, reports, and evidence methods.

Sources used

Source collections

Cite this article

International Marine Work Organization (2026). Ardrossan: Designing Passenger Access Around the Fleet. https://imwo.org/articles/article-ardrossan-passenger-access-envelope