By EMS : Electrical & Machinery Services Ltd Rotorua , New Zealand Some facts and background on the Tractionline winch assist product presented by EMS Managing Director : Chris Hancock
Who Are We and what do we know ? • EMS was founded in 1995 and has a long history with the forest industry and especially specialised cable logging applications. • Based in Rotorua, New Zealand and focused 100% on the forest industry • A small but very innovative customer focused company with 38 employees.
How the product Evolved Certainly EMS was not the first to introduce a winch assist system however pressure from our customers enticed us to take some interest in a project that had already been well and truly started. The result for us was the Tractionline by EMS. Research began, certifying engineers were engaged and a designated and recognised safety standard for manufacturing was agreed on , This being AS1418 which is a similar standard to ASME / ANSI B30 standard published in North America. All EMS Tractionline products are manufactured to AS1418
Why is a certification to AS1418 Relevant: • AS1418 relates to materials handling and personnel related winching equipment • This certification calls for a 5:1 safety factor on all elements within the build process. • This standard seemed relative and the closest possible standard to the application we were trying to manufacture for. • The specific emphasis of AS1418 is the safety and back up systems, braking systems and fastening requirements including cold temperature ratings.
AS1418 requires braking directly onto the drum flanges avoiding free spool situations should a shaft break or winch drive fail. Brakes are only applied in when the machine is shutdown, a critical alarm is detected or manually by the operator via the emergency stop. Eight brake actuators ( 4 per side ) are pressure released and spring activated providing the required safety redundancy.
The Myth : Tethered Machines are Hanging at full weight on the ropes The Truth : totally not true, the tethered machines tracks are always in contact with the ground. It is traction assistance not a dangle situation.
The Myth: If one rope breaks the second will immediately do the same due to increased forces. The Truth: The line tension required to drive the machine can be as high as 10 times the tension required to hold the machine in the same conditions and gradient. The line tension also assists the tethered machine from tipping backwards when climbing. One line is very capable of achieving this should there be a failure in either line. Fact : To gain an AS 1418 certification relative to personnel related winch systems, twin lines must be used. Fact : The most vulnerable area may not in fact be the rope it’s self but the termination of the rope end where it transitions from rope to a connection point. Fact: Ropes & terminations need to be checked daily and replaced as required. Not all ground conditions suit a steep slope tethering application where a unit may be working at 35 degrees plus , site evaluation and best practices still must prevail.
What's the best base machine to adapt the Tractionline onto ? • After much discussion it was decided that a 20 tonne plus excavator base provided the best and most versatile platform in our opinion. • The winch set, mast and ancillary equipment are easily adapted to an excavator base. • Hydraulic and electrical connection to the base are relatively simple and easy to achieve. • The excavator base remains manoeuvrable and capable of performing other duties. • A new base machine is certainly not required and a good used base is more than adequate and capable of handling the task.
Excavator General Installation
FEA Stress Analysis on Components
Lagged Winch Drums AS- 1418 Rating on all Components
Excavator Base machine Interface
Machine Positioning when working showing stress transition through the machine frame
Rope Angles and Sheave Blocks
Engineered Certified Attachment Points for Tethered Units with best possible stress distribution
Safety Features & Systems
Safety Features & Systems
Thank- You for your attention Any Questions ?
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