Introduction Barge and Ship Unloading Boom and Sheaves Bucket Dynamics Buckets and Attachments Center of Gravity Colour Scheme Components Contacts Control Systems Corrosion Protection Cost per Ton Crawler Hopper Cycle Calculator Directions to the Factory Disclaimer Dredging Alternatives Environmental Features Features Floating Cranes Fuel Consumption Gantry Base Cranes History Liftcrane Long Reach Alternatives Magnet Tables Maintenance and Overhauls Operator Comfort Optional Equipment Photographs PLM Lineup Prices and Lease Calculator Reeving Diagrams Scrap Handling Ship Conversions Stevedoring Rigs SU Dredges Swing Drive Transportation Arrangements Undercarriage Updates Used Equipment Video Clips Winch Construction Wire Ropes If the menu does not respond, right click the yellow bar directly below "Address" at the top of the screen and allow blocked content...click "yes" when prompted. Click the PLM logo for the home page. Please read our disclaimer. draglines, grab cranes, clamshell cranes, duty cycle cranes, dredging cranes, dredges, stevedoring cranes, stevedoring rigs, hydraulic cranes, marine cranes, ship conversions, 4 rope cranes, barge unloaders, dockside cranes, crawler cranes, harbor cranes, floating cranes, self-unloaders, plm cranes, pulleman, btc, pullemanbtc, plm, used cranes, used duty cycle cranes, bulk handling cranes   Duty Cycle Cranes for Bulk Handling A dilemma exists any time there is a need to buy new barge unloading equipment. What equipment is available, how much does it cost me initially and in the long run and who is going to operate it. Friction cranes are very popular however, most manufacturers went out of business at the end of the 1980s due to a number of factors such as inflation and the wide spread introduction to hydraulic excavators. The days of the friction crane are nearly over. It is hard to find a good machine and even harder to find someone to run it. Throughout the 1990s, modified excavators became available with material handling fronts which evolved into the modern day material handlers. These machines are readily available, are easy to operate and are fast but they have a lot of drawbacks. high fuel consumption (you move the boom as well as the load) short life expectancy (10,000 hr rebuild, scrap at 20,000 hrs) short outreach (50ft is the practical limit but 70ft is possible) high initial cost relative to machine size restricted ability to stack material outreach is restricted when digging below base When you look around, there are literally thousands of old style friction cranes running to-day that were built as far back as the late 1960s. These machines last 5 times longer than any material handler but are difficult to operate and are expensive to maintain and re-build. PLM Cranes of the Netherlands has the ideal machine which has all the advantages of an old style crane and all the advantages of a material handler. PLM builds hydraulic duty cycle cranes for clamshell work such as dredging and material handling. The machines are diesel or electric over hydraulic, power up, power down with all ropes on one layer of the drums. Any operator familiar with heavy equipment can become very proficient with a few days practice. These machines are like the old friction cranes in the sense that they last up to 100,000 hours or more but they are simple machines with very few components and operate like an excavator. The draw works consist of a diesel engine or electric motor powering a pump drive with fully enclosed planetary gearing on each drum. The systems are very simple, easy to maintain and easy to obtain parts. PLM uses suppliers such as: Caterpillar engines and crawler components Rexroth pumps and motors Lohman planetary drives Gates hoses Parker valves and solenoids These machines are built for operation on the open sea as ship's gear and dredging cranes where the risk of losing oil into the environment is a major concern. With an excavator or material handler, it is only a question of time before a major incident happens. These machines have high volume, high pressure hydraulics all the way out the boom with direct exposure. PLM cranes have all the hydraulics and coolants inside the machinery house which is designed as a saveall. In the event of a component failure, loss of pilot pressure shuts the crane down and any lost fluid remains in the house. Purpose built drains in the bottom of the house are used to remove the lost fluids. When you compare bucket size and outreach, a small crane can outperform a large material handler and last 5 times longer. Before you buy a material handler, check out the PLMs, you will be very pleasantly surprised. Advantages of a PLM over a material handler are: low intial cost and low operating cost environmentally safe low fuel consumption (you don't lift the boom) easy to operate (you will not be held for ransom by the need for high skill level) excellent outreach not restricted in outreach by depth above or below the base of the machine long life, up to 5 times longer than a material handler lowest cost per ton of all alternatives for barge unloading high reliability high parts availability simple, rugged construction. Of the more than 220 machines PLM has built since 1988, all are in daily duty cycle service. Most owners of PLMs own more than one machine and almost all PLMs are owned by the original purchaser.