Mechanical power transmission: Impact on the biosphere

Safe cable cars, wasted electricity and reused city pipes

What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).

Mechanical transmission has small direct footprints; its biggest environmental effect is indirect, through electricity wasted by inefficient compressed-air and hydraulic systems. Ropeways have a strong safety record per passenger, but rare failures are deadly.

Ropeway casualty rate (four Alpine-region countries, 2015-2022) 0.07 deaths and 0.65 injuries per 100 million passengers (buses and trams 0.18 and 7.49)²³ Medellín Metrocable certified CO2 reductions about 68,500 t CO2e, April 2010 to April 2017 (calculated; ex-ante estimate 17,290 t a year)²⁴ Potential US fluid power energy saving 0.4 to 0.8 quads a year²

Effects over time

Life affected	Short term	Medium term	Long term
Humans⁸²³²⁸	Construction of ropeway towers and stations; workplace hazards from rotating machinery.	In Germany, France, Austria and Switzerland (2015-2022) ropeways recorded 0.07 deaths and 0.65 injuries per 100 million passengers, against 0.18 and 7.49 for buses and trams and 0.09 and 0.93 for trains. A manufacturer reports that Medellín's lines cut some residents' commutes from over an hour to 10 to 15 minutes.	Rare catastrophic failures: 14 people died at Stresa-Mottarone in 2021 after a corroded haul rope broke with the emergency brakes disabled.
Animals⁷	Little evidence of effect.	Little evidence of effect.	Little evidence of effect.
Plants⁷	Clearance at tower and station sites for ropeways.	Little evidence of effect.	Little evidence of effect.
Fungi and soil life²	Little evidence of effect.	Little evidence of effect.	Little evidence of effect.
Ecosystems²⁴⁸²⁴	Little evidence of effect.	Indirect: fluid power uses 2 to 3% of US energy (calculated) at about 22% efficiency, so most of the fuel burnt to drive it is wasted. A manufacturer claims ropeways emit about 7.5 times less CO2 per passenger than buses (unsourced); Medellín's Metrocable received about 68,500 t of certified UN emission reductions for April 2010 to April 2017 (calculated from issuance records), below the manufacturer's figure of 121,000 t for 2010-2016.	Old pipe networks can be reused: London's hydraulic mains now carry telecom cables.

How the effects are reduced

The largest gains come from wasting less energy: fixing compressed-air leaks, lowering system pressure, using synchronous belts and choosing electric drives where fluid power is not essential. Ropeway safety relies on rope inspection (including magnetic testing), independent emergency brakes that must never be disabled, and regular maintenance checks. Historic networks show that old infrastructure can be repurposed rather than dug up.

Sources

Estimating the Impact (Energy, Emissions and Economics) of the U.S. Fluid Power Industry (ORNL/TM-2011/14), Love, Lanke and Alles Oak Ridge National Laboratory, 2012
London Hydraulic Power Company Science Museum Group Collection, 2025
Innovation in the air: using cable cars for urban transport World Bank (Transport blog), 2017
Urban ropeways: a solution for congested cities (manufacturer presentation) Poma-Leitner Group (hosted by Asian Development Bank events; not an ADB publication), 2017
Bus, train, ropeway: comparison of accident numbers and injuries (reporting a Technical University of Munich study) SI Magazin, 2026
Project 3224: Cable Cars Metro Medellín, Colombia UNFCCC Clean Development Mechanism, 2026
Mottarone disaster: 68% of the rope was already corroded before the tragedy L'Unione Sarda, 2022