The following are some questions to consider:
1. Is the manufacturer still in business? There have been many consolidations, closures and bankruptcies in the crane industry. Will you be able to get parts for your crane? Many of the older cranes are more robust and are a built-up design which allows you to buy many of the parts off the shelf due to them being industry standard components. This applies for motors, contactors, bearings, and couplings to name a few.
But, many of the cranes have components that were specifically made for the crane manufacturer and do not use standard components. You may have to make modifications to components to make the retro-fit parts fit correctly. Many crane manufacturers require special motor shafts, contractors, collector shoes, electrification systems to name a few which may or may not be readily available.
2. What are my liabilities if you buy a crane and make any modifications to it? Manufacturer’s liability is completely relieved once you modify their crane. Most used cranes will need some type of re-span which requires major mechanical modifications.If the crane is especially old, the box girders may be riveted girders which are difficult to modify, or arch beam type on patent track design which have been deemed unsafe. Properly done, an engineer will need to design and put his PE seal any modification to a bridge girder.
3. Is the crane the right capacity for my application? Bigger is typically better in crane applications but you need to consider the costs of getting a good deal on a higher than needed capacity? There are additional costs to consider. The crane is heavier and will require a larger runway and footings to support the dead load of just the crane. Every replacement part such as the motors, brakes, contractors, and wire rope all are larger and more expensive to replace. If you are making changes or upgrades to the electrical system such as variable frequency drives those components will also be larger and more expensive.
4. Does the crane match my existing electrical supply? There are many stories of a customer buying an old crane and then figuring out it is DC or the wrong voltage. You then face expensive motor changes or step up or step down transformers. Also is the electrical delivery system up to date. Is the electrification old open wire type, or an obsolete type of bar? It is very expensive to replace the electrical on an old crane.
5. Are you ready to give up the peace of mind of a warranty? They typically carry no warranty. New cranes now commonly come with 1 year parts and labour with an additional year on parts for all non-wear items. You also get up to date parts manuals so you can order parts from the manufacturer.
6. Who will do my modifications to the crane? If your crane does require a re-span or major electrical modification an experienced crane company needs to be involved. Where will the work be done? What are the additional costs of shipping including taking down the crane, shipping to a shop and then reshipping to your facility? Will a professional engineer stand behind all of the work? If the crane has problems once it is in the shop, who is responsible?