Dock equipment supplier DDL Equipment MD Andrew Stewart says that dock level- lers are underrated equipment in the materials-handling sector.

Dock levellers act as the bridge that links forklift trucks and highway trucks. Stewart comments that they are a vital link in the distribution chain, and, because of this, will always be an essential part of general industry, playing an important role in this chain. Further, he says, they are relatively inexpensive, and can stand up to considerable pressure from forklift trucks.

There are three types of dock levellers that can be used in this chain, the latest type being the inter- national standard two-cylinder, fully automatic, electro-hydraulic dock leveller with delayed lip action. This dock leveller can be electric or manual. Available prior to this was the one-cylinder dock leveller combined with a mechanical camb lip actuator and in 1950, two US companies developed the first fully mechanical dock leveller, in which the lift deck ramp and lip were mechanically actuated.

The one-cylinder dock leveller was only developed in the late 1970s, says Stewart. The cylinder is placed in the middle of the leveller to lift the deck, while the mechanism to kick out the lip is still maintained. At the time he says, a company manufactured an airbag to lift the deck in lieu of the one cylinder.

In the late 1980s, European manufacturers came up with the two- cylinder dock leveller, which was able to lift up the deck and auto- matically kick out the lip, says Stewart. This hydraulic power-packed dock leveller eliminated all moving parts. Having traditionally been placed next to each other, cylinders are now placed behind each other in centre position. In the early part of the new millennium, transferring all the dock leveller’s force to the middle gave it the best mechanical advantage, he continues.

Keeping up with the latest dock leveller technology is vital, comments Stewart. He maintains that dock leveller companies need to constantly bring innovations into dock levelling manufacturing, as was the case with his company, which has combined the hydraulic dock leveller power pack with the hydraulic door opener.

Stewart says there are close on 2 000 dock leveller manufacturers worldwide. A dock leveller is situated in the receiving and dispatch bay. The docking face is squashed between the rear of a 40-t truck and a heavy fork-lift truck which rides over the deck ramp of the dock leveller

Stewart never thought that dock levellers would be as widespread in South African industry, as they currently are today. He says that when he first introduced dock levellers to South Africa, in 1972, containerisation was a buzzword and the market was saturated. However, circumstances have changed considerably, and DDL Equipment now sells dock levellers to farmers, assisting in packing produce at the farmer’s door and the container is only opened again at the customer’s door and that’s what containerisation is all about.

Dock levellers should be manu- factured to last for as long as 25 years, says Stewart, but some companies also manufacture to only last five years, on what he calls a ‘contractor special’. The manufacturing of a five-year dock leveller is short sighted, he says, as this lesser quality dock leveller can cause serious safety issues, and will not last as long as the building it is supplying.

A recent development for DDL Equipment is retrofitting old dock levellers that the company manufactured for automotive companies, such as Ford, General Motors and Volkswagen in the 1970s. Retrofitting is becoming more popular in the industry, says Stewart, as not only is the chassis subse- quently stronger, but it assists existing users in updating the old dock levellers of 30 years ago to the latest inter- national standard, which is the two-cylinder in-line dock leveller.

DDL Equipment supplies dock levellers to many industries from raw materials, warehouses, and food processing to retail stores. It exports it products throughout Africa, and the Middle East, and is currently moving equipment into Angola and other Southern African countries, with current orders for Oman and Nigeria. Africa is the greatest potential of growth for the company, he adds, as there is a scarcity of dock leveller manufacturers in the continent.

The main challenge for DDL Equipment is keeping up with the latest global technology in dock levelling, says Stewart. To this end, he travels to international materials handling conferences and brings back technology he gathers from these conferences.

Abuse that occurs in the receiving and dispatch bay, which leads to accidents, is another challenge for the company, says Stewart. He attributes this problem to the speed of productivity, rather than the efficiency of operation, being the main concern for companies’ management. Fortunately, he says, docking equipment largely alleviates these problems, by preventing bottlenecks in the flow of goods and raw materials.

Each staff member employed by DDL Equipment, says Stewart, must be between 25 years and 40 years old, so that he can personally train and mould them to lead the company into the future. As proof of this policy, in the last year and a half, the company has employed six people, in that age category, in the sales, technical, production planning and service department of the company, he notes.