Chassis operations - Trucks and trailers for efficient containership turnaround
Truck-and-chassis operations have enabled the rapid growth of container terminals globally as a simple, cost-effective, and practical means of transport around a container terminal. Maintenance and operation costs for truck-and-chassis container terminals are low, and training for operators is straightforward.
Port superintendents are tasked with maximizing vessel turnaround efficiency. A pivotal yet often overlooked aspect of this process is the container terminal’s strategic management of chassis operations. We’ll delve into chassis use, compare the chassis with roll trailers, the issue of spatial challenges, underscore the importance of safety and efficiency in terminal operations and most importantly, highlight times when slowdown of operations may occur.
Containers being loaded from chassis in the Port of Los Angelese
(Image credit: Supply Chain Brain)
What are truck-and-chassis operations?
Any port where a container is carried by a trailer (known as a ‘chassis’), with the chassis being attached to a self-propelling truck, is known as truck-and-chassis operations.
For clarity, we will be referring to one truck attached to a single chassis capable of transporting one forty-foot container or two twenty-foot containers simultaneously.
Especially in North America, the chassis can also be called a bomb cart. According to a Heavy Duty Trucking article:
A chassis is euphemistically called a ‘bomb cart’… That term’s origin might be because it uses no tie-downs and instead cradles its cargo, like military munitions conveyances used to resupply fighter and bomber aircraft at air bases. Or, it’s because “they’re bomb-proof,” meaning very rugged.
In this article, we’ll refer to the trailer as a ‘chassis’ throughout.
Container movement and the integral role of the chassis
Chassis operations are fundamental to cargo movement within terminals. They’re specially designed for transporting containers from ships to their next mode of transport, such as front-end loaders, reach-stackers, straddle carriers and rail-mounted/rubber-tired gantries.
Several factors influence the efficiency of chassis operations, including the speed of chassis-tractor combinations, which is capped at terminal-specific limits to ensure safety (usually around 25-40 km/h [15-25 mph]).
Despite these speed limitations, focusing on minimizing chassis turnaround times—from when a container is offloaded to when it's ready for onward transportation—is crucial for reducing vessel berth times.
Spatial considerations in terminal layouts and cargo plans
The operational footprint of chassis operations significantly impacts terminal logistics, requiring extensive areas for manoeuvring, storage, and transfer activities. It is not uncommon to see long queues of chassis waiting to have their cargo transferred, especially on the quayside at peak times.
This extensive spatial demand can restrict the available area for other critical tasks, such as managing hatch covers or temporarily stowing containers on the quayside (such as unplanned restows). The importance of the chassis in terminal layouts necessitates innovative planning by the container terminal to optimize space utilization, mitigate congestion, and ensure seamless cargo flows.
Safety risks and efficiency opportunities in chassis operations
The proximity of terminal personnel to operational machinery for tasks such as removing twistlocks or stacking cones introduces risks that must be managed through terminal infrastructure, strict safety protocols and training. Enhancing safety measures protects workers and contributes to operational continuity and efficiency by reducing the likelihood of accidents and associated delays.
Observers of cargo operations - land or shipside - have a moral, ethical and operational duty to report safety infringements and opportunities to improve safety around chassis operations to the terminal representatives.
Terminals are moving away from riskier historical practices such as coning/deconing underneath the spreader of a gantry (fitting or removing twist locks and stacking cones). Protecting workers with segregated stations to cone/decone containers away from working spreaders and moving chassis is becoming increasingly common, and it can make operations more efficient by centralising labour-intensive tasks.
Night cargo operations at Da Chan Bay. The gantry crane is tandem-discharging containers, meaning the chassis need to be perfectly positioned to minimise spreader repositioning.
(Image credit: Logistics Manager)
When the gantry is operating in tandem spreader mode, then there is an increased risk to the chassis operators.
Roll trailers
In contrast to chassis operations, roll trailers are used when transporting oversized or non-standard loads that exceed the capabilities of traditional chassis. These versatile trailers are essential for handling specialized cargo. However, chassis remains the preferred choice for standard container movements due to their design efficiency, highlighting the trade-off between the adaptability of roll trailers and the streamlined specificity of chassis operations.
Generally, roll trailers will only be adopted for a cargo task when the cargo is non-standard. If the cargo is non-standard (such as an out-of-gauge or breakbulk), then it can be expected that cargo operations will be slow for the duration of the cargo moves involving the roll-trailer.
A roll trailer transporting a motor yacht in Port of Southampton (Image credit: Intelligent Cargo Systems)
When can chassis operations slow down?
Regardless of the speed of the truck and chassis, the planning and execution of cargo operations can have a direct effect on the duration and subsequent turnaround time of the cargo operations of the ship.
A few examples of when chassis operations can be slowed down are given:
Hatch cover operations
When a hatch cover is being discharged or loaded, the chassis transit area between the gantry legs is often forbidden to pass through. This is usually a safety consideration to prevent loose falling material from the hatch cover (e.g. twistlocks, lashing rods) from striking the truck or chassis.
Chassis transit will be delayed when the hatch covers are being moved. Depending on the terminal layout and available space, the chassis may also be diverted around the back reach of the gantry instead.
Berth delay may be experienced when opening all hatch covers on a single bay, especially if the chassis is transiting to high-productivity gantries, such as those discharging forties on deck.
Tandem lift operations
When gantries are operating in tandem mode, such as discharging/loading two forties, then the transverse spacing of the chassis on the quayside needs to be of good accuracy and repeatability to avoid any slowdown due to container repositioning and spreader locating.
Tandem gantries will often have digital aids to assist the sea-side spreader in attaching to the container. If the containers are out of position, this can take some time.
When discharging, the chassis positioning also needs to be accurate, as the container needs to land within the chassis correctly.
Dismissed gantries and shift changes
When a gantry is dismissed or moves to work another vessel, this shift in process can slow down the remaining operational gantries
As the gantry moves, it may temporarily block berth access for the chassis
Prior to and following a shift change, the chassis may require re-positioning
Depending on how the terminal operations are managed, chassis may be despatched/return to a chassis pool near to a staff building
Operations time will be used for the drivers to return the chassis to the pool, and vice-versa
Alternatively, the chassis may be left in-position from the last task designated to the chassis
This might mean that chassis will be left unattended on the quayside or access roads during the shift change
When the drivers return from the shift change, any unattended chassis may cause minor obstructions until their designated driver attends their chassis
Maintenance and breakdowns
Removing a chassis from operations can cause a delay if there is no suitable replacement.
If the truck/chassis breakdown in the operations area, it may also cause an obstruction, disrupting other active chassis
Weather
Rain, snow and ice can make the operations area slippery and increase braking distances. Chassis operators will travel slower to counteract this.
Rain, snow, mist, fog and sandstorms can affect operator visibility, and will likely lead to slower operations
Strategies for Operational Improvement
To tackle the challenges presented by chassis operations and enhance vessel turnaround times, several strategies should be considered and discussed with the terminal when the opportunity arises:
Optimized chassis pool management: Ensuring a balanced chassis supply to meet demand reduces wait times and accelerates container movements.
Technological advancements: Implementing GPS tracking, real-time status updates, and automated management systems can streamline chassis allocation and movements.
Space optimization: Reevaluating terminal layouts and employing advanced planning tools can alleviate space constraints and improve the efficiency of cargo handling operations.
Enhanced safety protocols: Investing in safety technology, continuous worker training, and rigorous enforcement of safety standards minimizes risks and supports efficient operations.
Collaboration and communication: Fostering strong communication channels between terminal operators and shipping lines ensures coordinated chassis use and reduces bottlenecks.
How can I be informed if chassis operations is below expectation and/or vessel completion time is in doubt?
Depending on your relationship with the container terminal, they may inform you when the completion time has changed, but they are unlikely to let you know when or why delays have happened. The cause of the delay may only be shared once operations are complete and the terminal departure report has been shared with the shipping company. At this point, the potential for remedial action has been lost.
Proactively monitoring and collaborating with the container terminal as they work your vessels can be the difference between on-time and costly, delayed departures.
Utilising a cargo operations monitoring platform such as CargoMate can provide a real-time view of the operations without needing the terminal to provide regular updates.
There are three details CargoMate measures which can indicate when there are issues with chassis operations:
Gantry performance for a single gantry is notably slower than the other gantries operating on the vessel
The crew and/or senior officers onboard have observed and noted an issue with the chassis operations
The berth performance following hatch cover operations has reduced
Using these three features, CargoMate ensures that port superintendents can monitor cargo operations with the right information at their fingertips.