There are numerous considerations that need to be taken into account when designing custom built crates [http://www.packnetltd.com/crating.html] for your product. One of the most important considerations when designing wood crating is to determine the mode of transportation. There may be various restrictions on the size of a package depending on how the product will be transported. In most cases a product will be moved via truck, and then either rail, ocean, air or a combination. Additional considerations may include reusable crating, handling restrictions at destination and within your own facility, temperature, humidity as well as shock and vibration concerns.
Once the fragility of a product is determined, the gross weight of a product and proper cushioning and preservation methods have been evaluated, one needs to consider the overall size of the finished crate. The outside height measurement is most likely the greatest factor in affecting how much (or how much additional cost) you’ll pay in transportation costs to move your crated product. In virtually every instance, no matter how large the product is, there are means and ways to transport extremely large crated products. You simply may be restricted as outbound flights or sailing dates are less frequent and more costly. Some common height restrictions for air bound shipments are based on the aircraft door openings. All crated product that is 64″ or less in height can be moved via passenger or cargo planes, and provide the most flexibility when shipping domestic or internationally. Other height restrictions are 88″ tall side door openings on DC-10 planes, as well as 96″ tall door openings in the nose cone section on 747 freighter planes. Main deck side door openings are 118″ tall as well on 747 freighters. Airbus planes are becoming more popular and freighter service will usually schedule 1-2 flights per week to most countries. There also are some crate length and width considerations to keep in mind. When shipping via air, it is highly recommended to keep crate lengths less than 120″ whenever possible. This is due to the fact that most bulky or larger crated products are secured to a flat rack or air pallet. This is a low profile heavy-duty aluminum or steel platform equipped with fittings that allow the pallet to be firmly attached to the aircraft deck. Air freight pallets are typically 10′ or 20′ in length. Freight is then normally secured to the air pallet with cargo netting and the use of tensioned straps. Airlines have been known to charge for two air pallet “positions” in some instances when a crate exceeds the 10′ length (even if only exceeding by two or there inches). This could be very costly!
Some common limitations for ocean bound freight exist as well. Most commonly used are 20′ and 40′ standard sea containers. Door openings are 94″ wide and 90″ tall. The entire inside width is 94″ as well. It is best practice to keep your crate dimensions a minimum of one inch under these dimensions to allow for dock plates and ease of loading and unloading. The available inside length of these containers is 19.5′ and 39.5′. There are also 40′ “High Cube” sea containers as well. They have the same 94″ width but offer an additional 12″ of height. It is best to keep your crate height at 101″ or less. Other options include open top containers (allow for taller product yet) and there are also new sizes of sea containers being introduced such as 45′ and 53′ long containers. It’s best to check once again with your freight forwarding agent and work with your crating specialist to determine your best options if you’re close to exceeding the standard allowed dimensions. For extremely large product that ships via ocean, it is often classified as “break bulk” and is stowed on the sea vessel alone and not inside of a sea container. It is usually lifted with overhead cranes and extremely large fork lifts. Lifting locations and appropriate markings are highly recommended.
When product needs to move from your facility it can be moved via truck with swing doors (usual height openings of 110″ and width of 99″) or trucks with roll up doors (usually 104″ tall opening). The other consideration when moving product via “low boy” (step deck) or flat bed trailers is that a permit is commonly required when the width exceeds 102″.
Some additional items to consider are markings, perishable cargo, liquid cargo, water damage protection, ISPM15 compliance and dangerous goods. Provide adequate ventilation for perishable cargo when required. We highly recommend use of moisture barriers such as MIL-J-131 water vapor barrier packaging with desiccant or VCI materials to protect products against moisture and corrosion. Investigate and be certain that no classified dangerous goods or hazardous products are improperly labeled (or not labeled at all) and that they are packaged in UN approved containers. Use of appropriate international markings such as orientation of the crating is highly recommended, as is the use of official ISPM15 markings by a certified crating supplier. There are currently over 134 countries that have adopted the ISPM15 standard for heat-treated lumber used in solid wood packaging. Furthermore, don’t forget your packing slips and export documentation as well with gross and net weights.
For very large or extremely heavy cargo you should check with your carrier or freight forwarding agent as well as a certified and experienced crating professional to confirm capabilities and booking information. Communicating and planning the shipment well in advance can save a significant amount of time and expense in the long run.