Fields of application are primarily areas in which no mechanical tamping is possible for economic or technical reasons. There are currently hand-held tampers with petrol engines or with electric drives on the market. The electrical devices have the advantage that the power source (motor or generator) is not directly attached to the device, however, there must be cable connections to the power source (risk of accident and obstacle). Hand tampers can, in principle, be divided into impact tampers and vibratory tampers.
This older method of sleeper tamping copies the process of hand tamping used in the pre-mechanical tamping with the tamping pick (tamping pickaxe). The first development consisted in an extension of the sledge hammer used for demolition work. The effect of these impact hammers is rather modest due to the conditions under which they are used. Basically, only one piece of ballast can be moved at a time and the ballast stones will be damaged and crushed by the striking movement of the ram. Also damage to the lower edges of the sleeper cannot be ruled out. Due to the point application, the ballast bed does not oscillate in the place where the impact tamper is used. This results in a rather low effect and degree of compaction.
Horizontal vibratory tamper
This produces a high-frequency vibration. The compaction of the ballast is caused by vibrations, which in comparison to the impact tamping, are more efficient. These vibrations are generated by an imbalance rotating around a horizontal axis. The disadvantage of this horizontal vibratory tamper is its awkwardness. The horizontally rotating eccentric including the protective housing needs a larger body of the tamper. In addition, the vibrations are not only produced in the ballast bed, but also the handles and therefore the operator is exposed to them.
Vertical vibratory tamper
An eccentric shaft produces the vertical vibrations, which make it possible for the ballast to move better and produce a suitable stabilisation of the ballast under the sleepers. The tamper is vertically positioned on the ballast and a small circular motion developed by the machine works automatically on the tamping tine in the ballast. When the necessary depth has been reached, the device is tilted by the operator. As a result, the ballast set in motion is compacted under the sleepers.
Advantages of the vertical vibratory tamper
The vertical vibratory tamper has several advantages.
- Damage to the lower edges of the sleepers is largely excluded.
- Use times for each sleeper are short compared to other handheld tamping devices.
- The ballast will not only be pushed under the sleeper but compacted by the movement in the sleeper crib.
- Vibration decoupling and the resulting lower vibrations on the housing provide for ease of use.
- Lower volume of the tool.
- Lower noise emissions.