Flatrack Packing and Lashing Guide

To pack a flat rack safely: check the flat rack first (valid CSC/ISO placard, corner castings, floor, end walls and lashing points), keep the centre of gravity central and the cargo resting on the two bottom rails, bed heavy items on timber that reaches the main girders, use anti-slip material so no metal touches metal, and lash with enough capacity: as a rule of thumb, the number of lashings on each side multiplied by their maximum securing load (MSL) must be more than the cargo weight. Depth Logistics specialises in out of gauge and heavy lift cargo and can arrange a marine surveyor to inspect your packed flat rack before shipment, from Brisbane, Darwin and Townsville.

Important information about this guide

None of this information is intended to replace or supplement any relevant or applicable regulation, guideline or code of practice whether or not referred to by us. This information is non-exhaustive and seeks to increase awareness of basic procedures and no express or implied warranties or guarantees are made. Whilst we have made every effort to ensure the content provided is accurate, it may, nevertheless, contain errors and regulations subject to change. Therefore please note that Depth Logistics does not assume any liability for the accuracy of the information and contents provided in this guide, or for any consequences resulting from using the information provided. Carriage of cargo is subject to our standard trading terms and conditions and no information herein is intended to alter or amend these.

Stuffing and securing your own cargo

All goods must be placed correctly and secured safely, allowing for vessel movement during the ocean voyage. Need a hand? Our team can pack or unpack your container in Brisbane or Darwin.

Checks before stuffing a flat rack

• Valid CSC/ISO placard (showing the date of validity)
• Corner castings and structure
• Floor and nails: holes, contamination or post-manufacture modifications
• Condition of the flat rack and lashing points
• End walls and locks
• Intended lashing equipment
• Cargo weight distribution and position

Centre of gravity

The centre of gravity is the mean location of an object’s weight, and it decides how stable your cargo is. Spread the weight both lengthwise and across the flat rack so the centre of gravity stays central; otherwise poorly secured cargo can come loose or tip as the ship rolls. For over-width cargo, do not pack blocking and bracing within 30 cm of the flat rack’s corner posts. Doing so stops the flat rack being stowed under deck, and on-deck stowage costs more. Out of gauge measurements must be accurate and include the lashing equipment. Incorrect declarations can lead to mis-rating and non-delivery of cargo. The floor is narrower than the container’s outer width (244 cm; 96″), so cargo may overhang the floor and still be in gauge. Only cargo or lashing that overhangs an imaginary line between the outer edges of the corner posts counts as over-width.

Welding and modifications

Modifying a flat rack in any way, including drilling holes or welding, is strictly prohibited.

Weight distribution

Flat racks carry heavier, more concentrated loads than standard containers. The two bottom rails provide most of the strength, so cargo must rest on the rails, or cross timbers must transfer the weight to them. Each flat rack is marked with a maximum payload, but the weight it can actually carry also depends on the length of cargo resting on the rails. Spread over the full length, the full payload can be used; very short cargo (for example resting on about 1 m) is allowed only about half the payload. Very dense cargo may need extra dunnage. Each piece of cargo should be assessed individually.

Bedding

Never place heavy weights directly on the wooden floor. Lay bedding across the flat rack so that it reaches the main girders and avoids point loads.

Anti-slip material

Metal-to-metal contact is not acceptable. Put timber dunnage or a similar anti-slip material (such as rubber) between metal cargo surfaces and the bottom rails. High-friction anti-slip material can reduce the number of lashings needed.

Lashing eyes

Flat racks have lashing eyes (D-rings), generally with a safe working load of 5,000 kg (this varies by manufacturer). Lashings stop cargo moving sideways or lengthwise and stop it tipping. Cross lashing is the most efficient method; downward direct lashings increase friction, and lengthwise lashings stop movement along the flat rack.

General lashing rules

• Protect web lashings on sharp corners.
• Avoid mixing lashing materials (for example wire and web) on the same cargo, at least in the same direction, because they stretch differently and create unequal forces.
• Avoid knots in web lashings: they cut breaking strength by at least 50%.
• Secure turnbuckles and shackles so they cannot spin open.
• Lashing strength is given as breaking strength (BS), lashing capacity (LC) or maximum securing load (MSL). For chains and web lashings, MSL is taken as 50% of BS. Manufacturers give a linear BS/MSL for direct lashings and a system BS/MSL for loop lashings.
• Poor lashing angles, sharp edges or small radii reduce these figures.

Securing cargo lengthwise

Use lashings or timber blocking and bracing. Timber bracing is common for crated cargo; the heavier the cargo, the stronger the bracing must be. Brace blocking against the corner posts. Unpacked cargo with suitable lashing points can be secured lengthwise with direct lashings alone.

Securing cargo against sideways and tipping forces

Cross lashing is best practice. Direct lashing needs lashing eyes on the cargo; use the “linear MSL” for calculations. For cargo without lashing eyes, use (half) loop lashing, also called lashing system, installed in pairs: one half starts and returns on one side, the other half on the opposite side. Use the manufacturer’s “system MSL” for calculations. Friction (top-over) lashings are not recommended because they don’t stop sideways movement, but they are acceptable for extra-wide cases.

How many lashings do I need?

Rule of thumb: the number of lashings on each side × the linear or system MSL must be greater than the cargo weight. This assumes an optimal lashing system; add more lashings for poor angles, wire bent around narrow radii or other less-than-optimal methods.

Pre-shipment inspection by a marine surveyor

Depth Logistics can engage a marine surveyor on your behalf to inspect your packed flat racks before shipment. The survey checks that irregular cargo has been stowed and secured correctly, and protects the goods and handling staff during road, rail and sea transport. If stowage or restraint does not meet regulatory requirements, the transport provider or shipping line will refuse to load the freight.

Out of gauge and heavy lift cargo from Brisbane, Darwin and Townsville

We move oversize cargo by road and heavy haulage to and from the wharf, and ship it by flat rack, roll trailer, roll on roll off or heavy lift ship. See our shipping container specifications for flat rack sizes and our container packing guide for standard containers.

Frequently asked questions