[haswell]

> "These newer units are safer as the doors have central locking ... In the past, the doors on slam-door trains could be opened at any time, even while the train was moving."

> "Due to a number of high-profile accidents in the 1990s, the manually-locked slam doors were supplemented with electronic, driver- or guard-operated central locking before they were gradually phased out in favour of sliding doors through the 2000s, resulting in a sharp decline in the number of deaths per year from passengers falling from trains"

> "Some units had individual compartments, each with its own door and no access to any other part of the train; however, these were unpopular due to security concerns and the lack of access to toilets ... The phase out was speeded up after the Murder of Deborah Linsley in such an individual compartment in 1988."

The Asbestos in many of these slam-door trains is less relevant to the central point, but was also a factor in the transition.

[hlandau]

The first quote is simply a statement that central locking is safer. I don't think that's really disputed, but it's not the same as saying that it was the defining motivation, especially in the 1920s.

The second quote relates to the greater adoption in the 1990s. But this is far after the initial adoption by the London Underground in the 1920s, and presumably these safety issues during the period 1920-1990 weren't so great as to be a showstopper, even if a safer design is preferable. This suggests to me that there was some other, much stronger motivating factor behind the development of the technology in the 1920s on the London Underground, with safety being a trailing motivator.

The third relates to a design issue entirely orthogonal to the design of the doors.

[haswell]

> presumably these safety issues during the period 1920-1990 weren't so great as to be a showstopper, even if a safer design is preferable.

Many things are not considered "showstoppers" during the early (or even later) stages of technology despite obvious ongoing harm. For example, there were 42,000 motor vehicle fatalities in the US in 2022. Despite this being a large loss of human life, it's not deemed a "showstopper", largely because we really don't have better options and because of the freedom that these vehicles enable. Now let's assume for a moment that self driving tech is perfected, and would theoretically cut down deaths by 75%. The safer design would be preferable, but for purely practical reasons would not be widespread for probably decades to come.

> This suggests to me that there was some other, much stronger motivating factor behind the development of the technology in the 1920s on the London Underground, with safety being a trailing motivator

How does this suggest that?

> The third relates to a design issue entirely orthogonal to the design of the doors.

The third relates to the cultural context driving adoption of updated designs, and the point is that this transition can't be reduced to any single factor.

I'm really trying to understand your position here, but you seem to continue reverting to your thesis and framing everything in terms of that thesis instead of explaining why the thesis is justified.

[hlandau]

The context of this discussion is my claim that "the adoption of electric, centrally controlled doors was naturally motivated in major part by timeliness."

You're claiming that this is refuted by the Wikipedia article, but I don't see any evidence for that. To be clear, I'm open to evidence that this isn't the case, there just isn't any there, because it discusses motives for adopting centrally controlled doors in the 1990s when the technology for centrally controlled doors was already widely available. It doesn't tell us anything about the initial motives for developing the technology for centrally controlled train doors many decades earlier, just that later on an additional motive showed up which drove some additional (late) adoption.

[haswell]

> The context of this discussion is my claim

Your claim is made in the context of reality.

Regardless of your claim or any of the objections to it, what happened in the 1920s happened. In principle, there's an answer to the question: "why did this transition happen?", and the goal of a conversation like this is to try to get closer to the truth. In practice, it's often hard to actually get solid answers without diving deep into the historical record, and rarely will there ever be a single traceable driving force or solitary "this is the reason".

You seem to be constraining the reasons you're willing to entertain to fit your opinions instead of finding the evidence to back them, and that's what I keep pushing back against.

The GP pointed out that there are indeed documented reasons for the transition that have nothing to do with timetables. So far, that's the only form of evidence that's been offered for any of the perspectives shared here. Simply restating your opinion and demanding the same kind of evidence that you have not yourself yet supplied is not sufficient.

> You're claiming that this is refuted by the Wikipedia article

I'm not (to be fair, it's possible that the GP was, but I don't know). I was reacting to this:

> I don't see anything to support this claim from the link you provide.

Bottom line: you wrote the article and made major claims about the nature of tech. The burden of proof is on you to justify those claims. Categorically rejecting actual evidence that may have explanatory value while offering no evidence of your own is making it increasingly difficult to take the position seriously.

The reality is probably some combination of all of the above: the newer designs kill less people, are more efficient, and satisfied a growing cultural discomfort with the perceived danger. The outcome of this combination is not purely good, or purely bad. It is neither oppressive nor perfectly beneficial.