Covid - they think it's all over

摘要

At the start of the pandemic, I suggested a quick response for railways would be to increase the amount of fresh air in vehicles and introduce some degree of partitioning (p9, June 2020 issue). It seemed obvious after the early problems of transmission in cruise ships that aerosol transmission in air conditioning systems was playing a part, and further research backed this up. That's not all there is to it, of course, surface contamination and direct droplet transmission are in there as well, tackled with improved cleaning and mask wearing. On heritage railways, compartment stock became gold dust and some dreamed of a return to soft padded compartments and opening droplights. The extra cleaning seems to have worked, as checks indicate most touch surfaces are clear of the virus (you can't test them all). Mask wearing helps contain the larger particles, but the aerosol particles float about at will and get recirculated in vehicle air conditioning systems. Obviously, the more fresh air is brought into the system the lower the risk, although we have no idea how big the risk is in the first place. Near the start of the pandemic the RSSB put out a work of fiction telling people it was safe to travel by train, this coming out about the time it clearly wasn't. The problem, apart from misuse of a slide rule, was the change in the'R'number, since a relatively small change in that changes everything really quickly.