The wear is accelerated by two main factors:

  • Floor deflection due to load weight: The weight of the load can cause the floor to bend, creating a small dent where the transverse stiffener is welded to the floor plate. This dent changes the direction of wear and increases the contact pressure, causing the area to wear out faster.
  • Heat from welding: The heat generated during welding can slightly change the properties of the steel. Whether this makes the steel more or less wear resistant depends on the material properties and welding parameters. If the heat affects part of the steel and makes it less wear resistant, the weaker part underneath will wear faster as the unaffected layer wears away.

This problem can be easily solved by adding a saddle plate under the floor plate as shown in the illustration.

The same problem can occur with the sidewalls. The deflection of the sidewall can create a dent around the weld line of the sidewall stiffener, exactly where the material properties have been affected by the heat of the weld.

Fortunately, the deflection of the sidewalls is much less than that of the floor, so the resulting dent is much smaller. Also, sidewalls are not subject to as much wear as the floor. Because of this, the problem occurs less frequently and only when the sidewall panel is relatively thin.

However, it is very difficult to attach a saddle panel to the sidewalls, mainly due to the lack of space or the existence of the bent corners in the sidewall, so a new solution is required.

Redesigning the sidewall stiffener as shown eliminates the need for direct welding between the stiffener and the sidewall.

Since the sidewall is not welded, its material properties are maintained and the wear resistance throughout its thickness is as high as other areas of the sidewall. In addition, since there is no direct welding contact between the sidewall and the stiffener, local dents do not form. This means that the wear rate remains consistent with other areas of the sidewall.

The general concept is to maintain a clearance between the sidewall stiffeners and the sidewall, thereby avoiding welding and the formation of dents.

Details such as the required clearance, whether the clearance should be filled with rubber pads, where the clearance should start and end, the shape of the clearance area and the design details at the start and end of the sidewall stiffener should be adjusted according to the specific characteristics of each tipper.

In the old design, the sidewall stiffener is completely welded to the sidewall, creating a closed structure.

As with the old version, the side wall stiffener of the new concept must also be closed to prevent dirt deposits or corrosion.

To achieve this, an additional plate is used to close the sidewall stiffener, as shown in the pictures. However, the closure plate should be designed according to the specific design of the sidewall stiffener. It can be welded to either the inside or outside of the stiffener.

Of course, the designer has more flexibility in determining the dimensions of the closure plate if it is welded to the outside. For example, locally widening the plate, as shown, can result in a smoother stress distribution and prevent stress concentrations.

The lower edge of the closure plate can either be bent or welded, depending on the space available and manufacturing capabilities in the workshop.

The following details can be customized based on the specific characteristics or requirements of the tipper:

  • Where the gap starts and ends.
  • The gap can be between the sidewall and side stiffeners, between the floor and floor stiffeners, or both, depending on where the problem is most likely to occur, as shown schematically.
  • Design details of the start and end points of the gap.
  • How much gap is required and whether the gap should be filled with padding (rubber, wood, etc.).
  • The pads could either be in direct contact with the sidewall or only come into contact when the sidewall elastically deforms under load.

Black dashed line: Weld. Red lines: Side wall, floor, top rail. Light blue: Side stiffener. Dark blue: pads

Black dashed line: Weld. Red lines: Side wall, floor, top rail. Light blue: Side stiffener. Dark blue: pads

  • In some cases, the tipper structure consists of two long beams. For Hardox® tippers, it is generally recommended to remove all stiffeners, including these beams, to allow the floor panel to flex when impacted. This minimizes dent damage.
  • However, sometimes these beams are required and are therefore welded to the floor.
  • Welding two strong beams (requiring four welds) to the thin Hardox® 500 Tuf floor can cause the floor to become uneven and have noticeable waves and height differences.
  • One solution could be to replace the C-profiles with rectangular tubes and use pads to ensure proper contact between the floor panel and the beams, as shown in the picture.
  • Another option is to use L-profiles. While this does not completely eliminate the need for welding between the longitudinal beam and the floor, it does reduce the amount of welding and makes it easier to control the heat applied.