Crane

A crane is a terminal lifting asset used to move containers or heavy cargo between a vessel, yard stack, truck, rail wagon, or handling area. In container operations, cranes are not just “lifting machines”; they are controlled resources in the terminal plan. Their performance affects berth productivity, yard congestion, truck turnaround, rail loading, and overall equipment utilization.

Where cranes are used in a container terminal

Different crane types are used at different points in the cargo flow. The main distinction is whether the crane works at the quay, in the yard, or at an intermodal transfer area.

• Ship-to-shore crane, also called an STS or quay crane, loads and discharges containers between the vessel and the quay. It is usually the most critical equipment during vessel operations because it drives berth productivity.
• RTG or RMG yard crane stacks and retrieves containers inside yard blocks. RTGs run on rubber tyres and can move between blocks; RMGs run on rails and are common in automated or high-density yards.
• Mobile harbour crane is used where a fixed quay crane is not installed or where the terminal handles mixed cargo such as containers, break-bulk, bulk, or project cargo.
• Rail-mounted gantry crane may be used at the rail terminal to load and discharge containers between rail wagons and the terminal yard.

How crane work fits into the terminal workflow

Crane operations are normally planned and controlled through a terminal operating system. The system converts vessel plans, yard positions, truck appointments, and rail schedules into executable work instructions for operators, equipment, and supervisors.

Typical vessel discharge workflow

1. The vessel plan is imported or created, including bay, row, tier, container ID, size, weight, and discharge sequence.
2. The planner assigns quay cranes to vessel bays and defines the expected working sequence.
3. The crane operator receives a move instruction for a specific container.
4. The container is lifted from the vessel and placed onto a terminal tractor, chassis, AGV, or other horizontal transport unit.
5. The system confirms the move and sends the container to an assigned yard location.
6. A yard crane stacks the container in the planned slot or updates the position if the move changes in real time.

Loading works in the opposite direction: the yard crane retrieves containers in the planned sequence, horizontal transport delivers them to the quay, and the quay crane loads them to the correct vessel cell. Good coordination is essential because one missing or late container can stop a quay crane even when the vessel is ready.

Operational example

A terminal is discharging a 9,000 TEU vessel with three quay cranes. One crane is assigned to bays 18–24, another to bays 26–32, and the third to bays 34–40. During discharge, the second crane repeatedly waits for terminal tractors because the assigned yard block is far from the berth and congested with import containers.

The planner checks the live operation and sees that average quay crane output has dropped from 31 moves per hour to 23 moves per hour for that crane. To recover the operation, the dispatcher sends additional tractors to the affected crane, changes the yard allocation for part of the discharge, and avoids sending more containers into the congested block. The issue is not the lifting capacity of the crane itself; it is the coordination between quay crane, transport equipment, and yard capacity.

Common planning and execution errors

• Poor crane split on the vessel. Assigning cranes too close together can create interference and prevent each crane from working efficiently.
• Wrong discharge sequence. If containers are discharged in a sequence that does not match yard capacity or customs holds, the yard may become congested quickly.
• Insufficient horizontal transport. A quay crane can only perform consistently if trucks, terminal tractors, or automated carriers arrive on time.
• Inaccurate container data. Wrong weight, size, hazardous status, or out-of-gauge details can cause delays, safety issues, or rework.
• Unconfirmed position updates. If a move is physically completed but not recorded correctly, the next retrieval may fail and create a search in the yard.
• Ignoring maintenance windows. Planning high crane demand without considering planned maintenance or known defects leads to unrealistic berth schedules.

Key crane KPIs and parameters

Terminals usually monitor cranes through a combination of productivity, reliability, and utilization metrics. The most useful indicators depend on crane type and workflow, but common KPIs include:

• crane productivity: gross and net moves per hour, often measured separately for quay, yard, and rail operations.
• cycle time: time from one completed move to the next, including hoist, trolley, gantry, spreader handling, and waiting time.
• Crane waiting time: minutes lost due to missing transport, blocked yard positions, hatch cover handling, vessel lashing, shift changes, or system delays.
• Availability: percentage of planned operating time when the crane is technically available for work.
• Move accuracy: percentage of moves completed to the correct location without rehandles, manual corrections, or inventory discrepancies.

Typical operational parameters also include safe working load, outreach, lift height, spreader type, twin-lift capability, lane coverage, block length, and travel speed. These parameters determine which vessels, stacks, or cargo types the equipment can handle safely.

Crane data in terminal software

In a TOS or terminal management platform, a crane is usually configured as an equipment resource with operating zones, availability status, technical limits, shift assignments, and performance records. Systems such as ContPark can use crane-related move confirmations, equipment allocation, and operational timestamps to support planning, billing, and performance analysis without treating crane activity as an isolated process.

FAQ

What is the difference between a quay crane and a yard crane?

A quay crane works at the berth and transfers containers between the vessel and the quay. A yard crane works inside storage blocks and moves containers between stack positions and trucks or terminal tractors.

Why can crane productivity be low even if the crane is not broken?

Low productivity is often caused by waiting time: no truck under the crane, blocked yard slots, vessel lashing delays, hatch cover moves, poor sequencing, or missing data. The crane may be technically available but operationally constrained.

What does “moves per hour” mean?

Moves per hour measures how many container moves a crane completes in a defined period. Gross moves per hour includes all delays during the period; net moves per hour usually excludes some non-operational delays.

Why is crane planning important before vessel arrival?

Crane planning defines how work will be split across vessel bays, how many cranes are needed, and whether yard and transport capacity can support the target departure time. Poor planning usually appears later as berth delays, congestion, and rehandles.