June’s New Civil Engineer had a diverse range of thoughts; speculation on the long-term impacts on aviation; HS2 debating whether trains and stations will need to be redesigned; Paul Sheffield reflecting on the balance of economic growth and carbon reductions and ‘how we can build a better new normal’.

Another magazine in my life is New Scientist and, interestingly, there is still confusion about how Covid-19 actually works. However, one recent article made clear to me a likely outcome for this pandemic is that the virus will change over time to join four other ex-deadly coronaviruses that now cause 20-30% of colds. 

Rapid viral evolution lies behind a pandemic. High population densities of animals and people living close together give the ideal conditions for this to occur. A place like the Huanan wet market had these conditions and studies show several intermediate viral variants had been circulating, finally allowing a deadly version to get established.

“The key here is that there is generally a trade-off between how lethal a virus is and how successfully it can spread. A pathogen that kills each host before it has time to infect other susceptible individuals will rapidly die out.” Where hosts are crowded together this doesn’t matter, but once a virus spreads to the wider population, natural selection will tend to favour strains that are less deadly. “Put bluntly, dead hosts don’t travel, and so don’t spread the virus to new susceptible hosts.”

As a result of this we have all probably had the 1889 Russian flu bug a few times. It is now just a cold, but as far as viral evolution is concerned, that is success. It is still alive and widespread! Covid-19 should eventually degrade in the same way, and New Scientist reports on some evidence that death rates are reducing already (although comparison of figures from around the world is tricky).

So, whilst I’m still concerned about when it is going to be safe to visit my 96-year-old Mum’s care home, do we really need to start redesigning our physical infrastructure in response? I can remember two other ‘we must change everything’ crises.

• Heathrow Mortar Attacks 1994: In the wake of this and other bombings it was suggested that buildings should be significantly hardened against this new terrorist threat. An excellent ICE paper (which I now can’t find) pointed out that the first Irish related London station bombing was in 1883, with more attacks in the following two years. Terrorism is not a new thing. Façade design for blasts become more sophisticated, but that is about the only long-term change introduced.
  
• The 9/11 attacks 2001: Immediately after the attacks these papers discussing radical changes to tall buildings including more and hardened (i.e. concrete) cores. After discussion, measures have evolved to become a clarifying of US approaches to disproportionate collapse – something that was already in UK codes after Ronan Point. Security at airports has prevented any similar attacks.

If we wind ourselves forwards by ten years, I think there is very little of our physical infrastructure that will need to change (assuming that Covid-19 follows the normal evolution). The discussion then becomes how long ‘short-term’ measures will need to last.

• We need to have an off-the-shelf draft pandemic response ready to use for when the next one comes along – because it will come eventually. It also needs to be kept maintained over the years – unlike Tsunami warning systems that fall apart because they aren’t used until they are suddenly needed.
• All the systems engineering and digital twin thinking now happening at places like the Centre for Digital Built Britain needs to rapidly developed. Our crisis response could have been so much better if this had been already in place.
  
• We need to start preparations for other low-probability, high impact events. What about solar flares? What about a widely successful cyber-attack?

Finally, there will be the things we want to change about life, society, fairness and the environment. But that is a list for another day.