Wednesday, December 18, 2013

Iron Profile: Marion 7200 Walking Dragline

The first Marion walking dragline ever built was still in operation more than 50 years later.


The 7200 Walking Dragline from Marion has long been revered for its durable and consistent performance, and with good reason. The first one ever made (ostensibly just a prototype) worked over 50 years, 6 days a week, for multiple shifts, which puts its productivity near 160,000 hours.

The original 7200 built in 1939 was equipped with a 100-foot boom and a 5-cubic yard bucket. Over the next 20 years many were sold, mostly with 6 and 7-cubic yard buckets. In addition to the electric machine utilizing Ward-Leonard drive, some were diesel driven. In the diesel configuration, they were equipped with 2 engines: a 300 horsepower Fairbanks-Morse 31A which was used to power the hoist and drag drums through clutches and brakes, and a 144 horsepower Cummins engine to drive a DC generator for the electric swing motors.

Primarily used in coal mining applications, the Marion 7000 series draglines were some of the most effective stripping shovels ever made. The 7200 was their second best seller with 57 units built between 1939 and 1957. They were also used for more generic material handling purposes, such as loading rail cars. Frequently this machine would be used to remove large quantities of sand and gravel overburden from the top of coal deposits.

There is a project underway to preserve the last known 7200 that hasn’t yet been scrapped. Let's hope it finds a suitable retirement for its historic life.

1 comment:

  1. I belong to a group in the USA, Ohio to be exact that has a Marion 7200 being preserved. We are in need a financial assistance in restoration. Information leading to donations can be acquired at HCRHP.org

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