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secret that may not be reproduced, disclosed to third parties, altered or otherwise employed in any manner whatsoever without the express written consent of R&M Materials
Handling Inc. Copyright 2020 © R&M Materials Handling Inc. All rights reserved.
2.5.2
Hoisting machinery designed working period (DWP)
Based on how the hoisting machinery will be used and on the actual hoisting machinery hardware supplied, the
manufacturer will agree the anticipated hoisting machinery lifetime or designed working period (DWP) with the
customer at the time of purchase.
The total lifetime of hoisting machinery consists of one or more Designed Working Period (DWP) where each DWP
typically lasts for around ten years when the equipment is used in accordance with the designed usage. It is
possible for different hoisting machineries on the same crane, for example main and auxiliary, to have a different
DWP. The DWP is the period in which, provided the equipment has been used and maintained in line with the
original expectations, the equipment can be safely operated.
DWP
= Designed Working Period
PGO
= Predicted General Overhaul
AGO
= Actual General Overhaul
T
= Time
In practice the lifetime of the equipment can vary due to changes in the environment and usage of the equipment.
For safety, in accordance with the ISO 12482-1 standard, it is important for authorized service personnel to
periodically check the equipment duty group and operating conditions regularly for any changes, then to revise the
remaining DWP% upwards or downwards accordingly. This action ensures that the equipment is kept operating for
as long as it is safely possible before a General Overhaul must be conducted.
2.5.3
How to assess hoisting machinery designed working period
The hoist service organization assesses the hoisting machinery Designed Working Period, but this table briefly
describes how it is done.
Product
Method
Product equipped with hour counter and log book
The remaining DWP% must be calculated in accordance with the ISO 12482-1 standard,
using the formula presented in the Appendix Designed working period (DWP)
Calculation.
Product with log book
Product without log book