DDL Equipment (Pty) Ltd

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Press Release - July 2008


Skeletal Trailer Has No Floor

Skeletal Trailer Has No Floor

The transportation of high cube containers on flat deck trailers has created challenges in the materials handling and logistics industry.

The problem with the height restriction of the high-cube containers is not the container height itself, but the flat-deck trailers, that are currently used by some contractors to transport the high-cube containers.

This not only creates a problem on the roads, where bridges have been designed in line with height restrictions as specified in the Road Traffic Act, but also at the premises of warehouses where these containers are delivered for loading and off-loading.

The trailers are simply too high. The industry accepts the high-cube containers, and has been accommodating them for years. When the containers were carried by skeletal chassis trailers at the industry standard height of 1 400 mm, the problem did not exist as the trailers being used were specifically designed for the purpose. They still met all the Road Traffic Act requirements.

While the 1 400 mm skeletal chassis trailers have been designed to be compatible with the containers and the industry height requirements, the 1 500-mm to 1 600-mm flat-deck semi-trailer often used in the industry has created numerous difficulties in the logistics process.

Transporting contractors that have the 1 500-mm to 1 600-mm flat-deck semi-trailer with no twist locks, which Stewart refers to as the lorry brigade, will, as a result of this laden trailer height, be over the legal roof height limit when transporting high-cube containers on national roads.

This trailer height does not comply with the road ordinance when used with the industry accepted high-cube containers, which have an industry standard maximum height restriction of 2 891 mm, and which is 300 mm higher than the standard container.

The total combined height of a trailer and container, as specified in the local Road Ordinance is 4 300 mm, which takes into consideration the industry standard ‘skeletal’ trailers, with a ground-to-floor height of 1 400 mm, and the International Standards Organisation (ISO) high-cube container, at 2 891 mm, giving it a total height of 4 291 mm.

Showing the Extra Container on

Showing the Extra Container on 

the Flat Deck Trailers

Most reputable transporters have the standard ISO skeletal trailers which, admittedly, are a specified trailer for containers, and cannot be used for general cargo as the skeletal chassis trailer has no solid flat deck. A demountable slave deck should be used to convert a skeletal trailer to a flat-deck trailer by placing a floor from150 mm to 200 mm in height on the existing trailer, incorporating the corner-twist locks. In this way, a skeletal trailer can be better used for all cargo.

When an ISO container is placed on a flat-deck trailer, it places a second floor on top of an existing floor, and an already high trailer, which exceeds the legal requirements, and creates problems in loading and off-loading.

This second floor increases the floor height to over 1 600 mm resulting in problems with loading and off-loading at the one million loading docks, around the country, as the receiving and dispatch bays have standard dock heights of 1 350 mm. This increases the gradient to above 10%, which is too steep a gradient to allow forklift trucks to ride up over a dock leveller ramp into the container.

The use of standard docking doors, which are 3 000-mm wide and 3 000-mm high, and totalling 4 350 mm in height above the ground to allow a rear container door to swing open out into the loading bay, does not function with the use of a second floor on the trailer.

The roof height of a container will now be well above the standard door height so that the container doors cannot open, which also causes damage to the top lintel of the door when the 40-t trailer approaches the building from its rear.

The refrigerated and deep-freezer warehouses create another problem for the flat-deck trailer and high-cube container combinations as these warehouses, which include food processing, abattoir and fruit farms, have ISO and Road Traffic Act regulation building standards and design specifications that renders any vehicle over 4 300 mm incompatible with the warehouse loading and off-loading processes.

In addition to these concerns, shelters and canopies at the docking bays are designed and built to standards to comply with distribution vehicles, materials handling equipment, docking bay openings and building requirements.

These heights may vary between 4 500 mm and 4 800 mm above ground. Architects, consulting engineers, project managers and construction companies from conception, have been specifying these dimensions for weather protection, as well as to prevent ingress of rain, wind, dust, pilferage This also applies to bridges, subways, overhead walkways and tunnel design specification.

There should be no concerns regarding the high-cube container height and its use with the standard skeletal trailers in view of the South African existing road ordinance and international standards for vehicle trailers carrying containers on South African roads.

Height Differences between Dock and Container Floor

The only difference between a standard container and the high-cube container is the height of 300 mm higher and is not new to containerisation. The ISO high-cube container has always been around since the early days and is not an exception.

Most chilled, refrigerated and deep freezer cold store warehouses as well as food processing, abattoir and fruit farms etc. have dock sealing systems to conserve energy so as to adhere to the Cold Chain and HACCP. The designs and building standard are specified around ISO and Road Traffic Act regulations and their specifications. Any vehicle over 4 300 mm above ground height will impact, damage and interrupt the successful handling of products at the docking bays.

Stakeholders in the transport industry, and the materials handling and logistics industry, are set to propose changes to the legislation with the possibility of changing the trailer design to make them lower or to place a moratorium on the prosecution of offenders.

When the tenders for the manufacture of the skeletal chasses container trailers went to parliament for approval, I was given a copy of the drawings to peruse for comment. I found that 400 mm from the twist locks was added onto the rear-end of the trailer. When I questioned this measurement, I was told with is for "aesthetics" and for stevedores / packers to stand on. Pointing out the folly of this extension, that it would be impossible to off-load containers by means of docking equipment, forklift trucks or other materials handling equipment, the drawings of the skeletal trailers were altered to suite the white paper and the amendments were sent to parliament. For a while this was know as the "Stewart side" (rear-end).

We now hear of the "pending" changes in the Road Traffic Act. There are concerns that at the coastal harbour port points of the road haulers or carriers, traffic are being given fines for offences of the over-height rules of the law, and that the Department of Transport (DoT) has been approached to have traffic police be more lenient on transporters. Permits for abnormal loads are not being applied for and are being ticketed for contravening the laws.

Possible amendments to the regulations of the Road Traffic Act will be argued by the Institute of Road Transport Engineers, the Harbour Carriers Association, Road Freight Association, DoT, the Chartered Institute of Logistics and Transport South Africa, and other professional bodies and trade associations, who have all been called to discuss possible amendments to the regulations. However, the industry does not believe the system needs to be changed.

The South African industry complies with the ISO, and changing the law to handle higher vehicles may not be the solution that some believe it will be, but on the contrary it will increase unnecessary changes, high costs of implementation, a higher centre of gravity causing accidents which are already prevalent on our national highways due to jackknifing accidents of truck and trailers, winds, overturning, load shifts, a domino effect which will occur with the cost of changes to the docking bays, docking heights, docking bay doors among other things, which is not possible.

Lawbreaking transport operators, currently undertaking to carry steel containers on steel flatbed trailers without twist locks, should be informed and educated about the regulations and procedures for materials handling and road cargo transportation as stipulated in the Road Traffic Act.

The policing and informing of the existing laws through the body or trailer manufacturers, truck companies and transport consultants, to provide the idea of using a slave floor to better use the transporters or carriers, haulers fleet of existing trailers. This is the most simple and effective solution to the problems.

In 1969 the first container seminars were held around the country. When the concept of containerisation was officially launched in South Africa in July 1977, it was recognised as one of the finest achievements in the world.

It is successfully surmounted the many unique problems facing the local industry, to create a system which confirmed fully to international standards. The trade imbalance which was weighted so heavily in favour of imports caused a huge build-up of empty containers, an issue which had to be addressed.

The fact that 60 – 70% of all business is done on the Reef which is 600 kms from the nearest coastal port of Durban and 1 200 kms from Cape Town resulted in the creation of the largest in-land port in the world at City Deep. Nowhere else in the world did this problem exist.

To overcome the build-up of business between the inland port and the coast, South Africa developed liner trains which were skeletal rail wagon from City Deep to Durban, Port Elizabeth and Cape Town to meet the cellular container ships.

The industry also developed road skeletal chassis trailers to international standard so that in every way South Africa met the standards of its global trading partners. The problem of South Africa’s narrow gauge railway line was overcome through the development of special bogeys for skeletal wagons, but 25 years down the line. South Africa is breaking all the rules to the detriment of exporters. There has been such enormous growth in the containerisation concept from it’s early beginnings that one has to be critical of the deteriorating standards in South Africa and Spoornet, has much to answer for this.

Export today have risen ten-fold in the last quarter century, particularly perishables and agricultural exports, and this is presenting a problem. The railways have inherited a fine system with the whole infrastructure to handle containers by rail over long distance to the port, but it’s not being implemented.

There is a massive build up of empty container depots on the Reef while road transport is moving breakbulk loads to ports, warehousing it and loading containers for overseas, and bypassing the port of City Deep. Perishables, for example are moving from the Northern Province to Durban, Port Elizabeth and Cape Town by road. This is not only leading to congestion of the road system but means double handling of the product which in turn results in a shorter shelf life. This is getting away from the door to door concept or the moving storage warehouse and adding costs to the South African product. Producers and manufacturers want to go back to rail and in fact need to be re-educated.

But clearly, issues of inefficiency and poor productivity must be addressed to the satisfaction of its customers before South Africa’s railway system is again utilised at its full potential.

The inefficient use of local rail transport is having a negative effect on the containerised transport of goods, while road transport cannot offer the same benefits as rail when it comes to containerised goods.

The decline in the use of rail transport has not only resulted in congestion on the country’s roads, but is also negating some of the benefits of containerisation, which should be a door-to-door service.

The fewer times cargo is handled, the less it costs. Instead, the prevalence of road transport has resulted in the increase handling of goods, which is pushing up costs. Some road freight operators do not load their trucks according to recognised standards, making it difficult – if not impossible – to unload the cargo using standard equipment. This can cause delays which influence the quality of the cargo, especially in regard to perishable goods.

Again, I call upon all stakeholders to unite under the umbrella of materials handling. Implementing similar materials handling standards will create efficiencies along the physical distribution system, from raw material to point of sale.

These standards should not only benefit local industry, but should also comply with international standard in order to assist South Africa’s materials handling industry to compete in the global market place.

The focus in the materials handling and logistics industries has shifted to Information Technology, which results in the fast tracking of information, but offers no real solution to road congestion and inefficient use of rail infrastructure..

Many stakeholders in the industry seem to have lost sight of the fact that:

Materials Handling and Transport IS the hardware that drives the logistics and supply chain software


Issued on behalf of:

Andrew TC Stewart Tel: +27 11 443 4233

DDL Equipment Fax: +27 11 882 4569

PO Box 210 E-mail: ddl@icon.co.za

Strathavon 2031

South Africa

March 2006

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