Early Container Equipment

file photo
file photo

Published Nov 12, 2019 7:12 PM by Joe Zehner

I began my shipping career in 1965 in New Orleans. At that time containers were about eight feet long by six feet by six feet containers which we called conex containers or boxes. These were used by the U.S. military and also by some commercial carriers. They were successfully used by the U.S. military beginning in WWII and then in Korea and Viet Nam. 

Later came many variation of the intermodal shipping container we are familiar with today. Most commercial shipping lines who used them leased them at a per diem charge from container leasing companies. The company I was with at the time represented service to Chile. Cargo was stuffed into these conex containers at the pier. These units can hold about 9,000lbs of cargo.  


The concept of putting cargo into a “container” often in the form of a box or crate in order to protect it and to facilitate handling and loading and discharge from conveyance was not new. But the idea of a reusable shipping container of a standard size able to be handled by standardized equipment worldwide was new.  At that time most containers were 20 foot containers meeting ISO standards. ISO stands for International Standards Organization which stipulated 10 foot, 20 foot, 30 foot and 40 foot containers.  

These containers were to be built with standard outer dimensions and to have an ISO corner casting on all eight corners. This proved to be key to developing standardized equipment to handle and secure these containers. Eventually 20 and 40 foot containers proved to be the most effective although a major west coast carrier had a fleet of 24 foot containers, and a major U.S. Gulf based company built a small fleet of 30 foot containers.  

Container fleets also over time reflected the need for specialized containers. For example: flatrack containers allowed oversized cargoes to be loaded from the side. Platform containers allowed cellular container ships to make temporary decks to carry oversized, out of gage, cargo inside cellular hatches.  Open top containers allowed oversized material to be loaded from the top and if necessary extend above the toprail of the container using tarpaulins to cover the cargo from the elements. High cube containers allowed more cargo high in cubic but less in weight to be loaded into 20 and 40 foot units.  

Tank containers permitted liquid cargoes to be carried in small quantities without the need for drums.  This was especially true for hazardous liquids as the outside frame of the tank container partially shielded the tank from damage and made handling safer. In the early days many hybrid containers were experimented with including containers made of fiberglass reinforced plywood which had problems with sealing the plywood and fatigue from frequent handling. Containers with peaked ceilings to keep condensation from dropping onto the cargo, this reduced the interior capacity of the container and did not work well.  

A carrier serving Australia had a fleet of insulated containers for transport of frozen beef Northbound.  These units had “T” rail floors, as found in refrigerated trailers and had two ports on the front of the unit. When the frozen beef was loaded into the containers they were immediately loaded to the vessel and hoses were attached to the ports in the container and cold air was pumped into the containers from ship's refrigeration units. When the units were discharged and waiting to go to cold storage a liquid oxygen bottle was hung on the front of the container and dispensed cold air into the unit. When the frozen beef was removed the unit was cleaned and used for dry cargo Southbound. There were and are units with refrigeration units built into the container which run on diesel while moving overland and can be plugged into shore based power or ship's power, when onboard, and run on electricity.  


The ISO intermodal container is basically a box, in order to move the unit over road and street a chassis is needed. The ISO intermodal chassis resembles a frame with wheels at the back and a “king pin” at the front. The king pin is what the truck tractor attaches to the haul a semi-trailer. Most lines used leased containers at a per diem charge and also leased chassis to move them, containers could also be moved on flatbed trailers, but securing was always a concern.  

The 40 foot container on chassis resembled a highway van, the 20 footer being only about half the size. To accommodate the 24 foot containers some chassis leasing companies produced a chassis with support arms at 20 feet and 24 feet measuring from the rear of the chassis. The chassis was designed to allow a truck to back the container to a loading dock to open the doors for loading and discharge of the cargo. These specialized chassis were equipped with “pyramids” at the ends of the support arms to be used for securing the containers using the ISO corner casting which is the essential feature of all modern shipping containers. This corner casting is located at all eight corners of all containers and allows standard lifting and securing equipment worldwide to handle them.  Some leasing companies had 20 foot chassis equipped to handle the 24 foot containers which had a rotating pyramid to allow it to become flush to clear the 24 foot container's bottom rail.  

Today all chassis have a “twist lock” type pyramids to secure the container to the chassis but in the early days the pyramids did not swivel but were fixed with a lateral hole shaped like an inverted keyhole. A piece of steel rod with a perpendicular handle which was attached to the chassis by a piece of chain welded to the chassis was used to lock the container onto the chassis. The rod had two small posts which went through the keyhole shaped fitting and kept the rod from coming out. When there was no container on the chassis these locking pins would often dangle by the chain and break tail lights and reflectors or just break off. It was not a good method.  

Twist locks shortly followed which greatly improved the safety of carrying containers on chassis.   Other improvements were the gooseneck chassis which allowed the high cube container to better meet road bridge height clearance restrictions and 40 foot chassis with eight support arms to accommodate 1 X 40 foot container or 2 X 20 foot containers. 

Also tri-axle chassis were developed to handle very heavy containers and are used almost exclusively for ISO tank containers.  Chassis with slider boggies (semi-trailer wheels and axles) also assist in distributing the load to meet highway weight restrictions. Containers have strict weight limitations marked on them, but all U.S. States have different road weight limits which are monitored closely.  Innovations in chassis and other container handling equipment are constantly being developed to improve the efficiency of container handling.  

Maintenance of chassis is always a headache as they change hands so many times in their overland travels. In addition to glad-hands and hoses, brake systems, lights and reflectors and mud flaps there is the maintenance of tires. Checking to be certain that tires have not been swapped by overland carriers and for road damage and wear. Management of chassis fleets was and remains a challenging process.  With the advent of computers this has become much more efficient.  

Intermodal Movements

The term “inermodal” means just what it says. Containers are often shipped intermodally, that is by ocean, truck, rail, back to truck for delivery to customer's door. Containers moving from the seaport to short destinations generally  overland by truck. Containers moving to farther destinations inland generally move by rail and in some cases by barge. Land bridge began with containers from the Far East moving from West Coast ports to the East Coast U.S. Via rail. Then came “mini-bridge” which then included West Coast movements to the U.S. Gulf. These were very strange concepts when they first appeared but are now very common place.  

Rail Moves

Highway trailers had been carried on railcars for quite a while and were mostly loaded at a “circus” ramp. This method was heavily used during WWII for movement of military goods. This facility was called this because circus wagons which traveled by rail flat car were loaded this way. Highway trailers eventually moved by this mode as well. This term may seem very strange now, but it was used a lot in the late 1960s and 1970s.  

This is really the history of what became container on flat car and trailer on flat car they were moving “piggy back.” Railroads developed cars with two collapsible “fifth wheels” the horseshoe fitting you see on the back of a semi tractor rig, which engages the king pin, were use for trailers, and later containers on chassis onto railcars for movement between cities and to seaports. 

When containers were loaded onto railcars while on a chassis they moved trailer on flatcar or TOFC. When containers were loaded onto flatcars without chassis they were being moved container on flat car or COFC. This became typical as container lifting equipment developed. Now “double-stack” unit trains transport ocean and domestic containers (a hybrid of the ocean container some up to 53 feet long) move coast to coast at priority speeds on “unit trains.” This is not the “old days.” 

Container Handling Equipment

In the early days there were many attempts at designing equipment to transfer containers from ground to chassis and from chassis to railcar or flatbed truck for intermodal movements. One odd unit was the  side loader truck which could load a container from the ground onto it's bed and then drive beside a chassis or flat bed or railcar and off load it with it's self sustaining apparatus. It did not get wide use. It was slow and costly.  

Straddle carriers were also developed and are in wide use now but were expensive. Most ports in the South used heavy capacity fork lifts, early containers had fork lift pockets in the bottom rail to facilitate handling by fork lift. These were replaced by top loaders with electrically operated twist locks and capability to change lifting frame from 20 foot to 40 foot.  

Container Stuffing

Container stuffing vs. container stowage refers to the loading of cargo into the container. It is essential that cargo is loaded evenly into container to avoid imbalance when lifting and handling the container.  Securing of cargo inside the container is also essential to keep it from shifting inside the container which can cause damage to the cargo and container and cause a serious safety hazard. In the early days shippers who had made many truck shipments were familiar with securing cargo for road transport but containers at sea are subject to additional stresses.  

The presence of Hazardous Material in containers is closely regulated and must be documented as per strict regulations. Certain cargoes cannot be placed in proximity to others. If this is not possible within the limits of the container the other cargo must be in another container or not shipped. Containers with Hazardous Material must be properly placarded. If the proper markings are not displayed on the container it cannot be shipped.  

Container Stowage

While the first acknowledged container ship was actually a converted tanker and loaded containers under deck, in the early days most containers were loaded on deck with very few loaded under deck as the equipment for handling them was not fully developed as yet and vessels not designed to accommodate containers under deck efficiently.  

Breakbulk or tween deck ships of the early post WWII period sought to minimize the size of the hatch opening to offer more sheltered stowage in the “wings.” This made it difficult to stow containers other than in the square of the hatch. Loading containers onboard tween deckers was often done with use of shore crane. This was prior to development of cellular container ships. Modern breakbulk ships have open hatches and cranes with sufficient lifting capacity to accommodate containers.

Container Management

Containers and chassis all are numbered with a unique system of alpha and numeric, this is the only effective way to keep track of them. One digit or letter mis-recorded can cause huge problems. While now many containers are equipped with a computer read number in the old days the container number was sighted and hand written in many cases. The “check digit” usually caught the fact that the container number was wrongly recorded. In many cases someone had to actually go look at the unit to confirm the correct number.  

When I first started in shipping we kept track of this equipment on 3 X 5 index cards kept in a recipe box on the corner of my desk. Now container and chassis fleets are tracked with some of the most powerful computers available. In the early days containers were parked on open piers or inside the cargo sheds beside breakbulk cargo, now container terminals with specialized equipment of all sorts is used to dispatch the container ship as quickly as possible. The loss of a few minutes is deemed too much. Things have changed in the container business.

Container Ships

In the 1980s a 1,200 TEU container ship seemed very large; recently a container ship with the capacity of over 23,500 TEUs transited the Suez Canal. Ships will be discussed in a future paper.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.