A storage and retrieval machine (SRM) is a storage device with which load units can be stored, transferred and retrieved. The storage, transfer and retrieval performance of a storage system depends on the following factors of the storage equipment used: Storage and retrieval machine

  • Construction
  • Behavior
  • Aisle dependence
  • Load handling attachments

The number of storage devices also plays a role. In addition to storage and retrieval machines, high-lift trucks, satellite vehicles and forkliftscan be used.

Storage and retrieval machines can be moved in three directions.

  • In longitudinal direction
  • In a vertical direction
  • In transverse direction

It consists of mast, chassis, lift truck, load handling device and control system.

Storage and retrieval machine

Use of a storage and retrieval machine in an automatic small parts warehouse ( Image license: CC BY-SA 3.0, Author: Thomas Philippi

When a storage and retrieval machine is moved in the longitudinal direction of an aisle, this means that it transports inventory on a rail along an aisle. In the vertical movement, it moves along a mast and it moves in a transverse direction, e.g. if a pallet is to be picked up or put down.

The travel speed depends on the direction in which the storage and retrieval machine moves, the payload and the total weight. Storage and retrieval machines sometimes have to cover long distances and ultimately position the inventory with millimeter precision. They have a lifting height of 6 meters up to 50 meters.

Curved and aisle-bound storage and retrieval machines

Curve-going SRMs can be used in low-performance requirements. The storage aisle can be changed with the help of a relocator, i.e. via a rail network laid on the ground. This means that the storage and retrieval machine can travel through several storage aisles. According to their designation, aisle-bound SRMs are only ever used in one storage aisle. The use of an aisle-bound storage and retrieval machine is suitable for high-performance requirements.
A storage and retrieval machine can be controlled manually or automatically. Automatic control can be implemented with the support of a warehouse management system.

More information can be found under resource utilization in material flow control.

Image source: © Corepics – Fotolia

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