In a 2015 study of late nineteenth-century subterranean urban rail ventilation in London, engineering historian Arthur Pendelton examined the mechanical air-shafts constructed along the Metropolitan District Railway. Pendelton documented that while early steam locomotives relied primarily on passive chimney flues to vent sulfurous emissions, the 1883 introduction of powered fan impellers at the Charing Cross station reduced localized carbon monoxide concentrations by thirty-four percent. However, Pendelton emphasized that this installation was restricted exclusively to below-grade platforms and was not deployed within the connecting passenger concourses. Furthermore, despite contemporaneous claims by railway directors that the impellers operated continuously, maintenance logs revealed that power to the ventilation turbines was routinely suspended during non-peak overnight hours to conserve coal reserves.
Consider each of the choices separately and select all that apply.
Which of the following statements regarding the 1883 ventilation impellers at Charing Cross station is explicitly supported by Pendelton's findings?
- They contributed to a quantified decrease in carbon monoxide concentrations on subterranean station platforms.Answer
- BThey were integrated into both below-grade platforms and adjoining passenger concourses.
- Their power supply was routinely interrupted during overnight non-peak hours.Answer