What does "Passive Provision" mean?

[whole diary]

[grahame]

I understood that "passive provision for xxx" meant that works being done would be done in such a way that they made allowances for xxx to be done in the future and didn't add obstacles to be added to get in the way of the future.



It looks to me that this trunking will get it the way if loop is added to serve the third platform at Chippenham (the HST^▸ (High Speed Train (Inter City class 43 125 units)) is sitting at the current platform. 

Is this just a temporary installation, have we been sold a "pup" in the promise of passive provision, or have I misunderstood what "passive provision" means?

[ChrisB]

The way the trunking moves towards the platform on the right makes me think that is provisioning. Otherwise it would simply carry on in the arc that you can see

[TonyK]

I don't think the example above contradicts the principle of "passive provision" because that trunking isn't a substantial impediment. It may be that the cabinet it leads to would need to be moved if the loop happens, and can stay there at zero cost until then.

However, I found a better demonstration of the principle in my former home town of Blackpool. This set of points appears to lead to nowhere:



It was installed, along with others further along the track turning towards the same direction, at the time the tramway was updated in 2011-12. The idea was to leave "passive provision" for the reinstatement of the link to Blackpool North station, lost 80 years ago, along Talbot Road. Should the work be approved, it can be done with hardly any disruption to the running of the existing tramway. The cost was negligible in the overall project budget, certainly when compared to what it would have cost later.

In one sense, it should be seen as "active provision", IMHO^▸ ('in my humble opinion'). It served as a reminder that there was a case being made for the new link, and that one of the obstacles had been removed, rather than no new obstacles had been added. I am happy to say it was successful - the plans have been approved, the funding secured, and once the legal niceties have been dealt with, work should start later this year.

See also a post on a forum about the project.

[SandTEngineer]

Its only GRP cable route on concrete supporting legs with a few cables in it.  The business case probably said it will be cheaper to demolish it all and start again if needed 

[Tim]

You are right to raise the question.  There may have been a failure on passive provision here.  Although it looks like a very minor one.

The blue lid is a drainage inspection cover which makes me wonder if that drainage may need to be moved too?  If that is the case then "passive provision" wrt the trunking might be simple sticking it in a position to make moving the drainage easiest.  

[SandTEngineer]

You are right to raise the question.  There may have been a failure on passive provision here.  Although it looks like a very minor one.

The blue lid is a drainage inspection cover which makes me wonder if that drainage may need to be moved too?  If that is the case then "passive provision" wrt the trunking might be simple sticking it in a position to make moving the drainage easiest.  

....but passive provision costs money now, and how many times have we seen in the past where passive provision is made and it never (never) happens or things get changed in the interim period?  Ultimately, there may not be funding available in the first project to think forward like that, and if initially there was, its quite likely that it would be identified as a potential saving during the GRIP^▸ (Guide to Railway Investment Projects - Network Rail's process for project management of schemes through development and implementation) development process and eliminated from the scope accordingly.

[ellendune]

I think you have to balance the additional cost now with the additional cost later.  Trunking is not that expensive to move. Putting a structure there might be a bit different. 

[Tim]

....but passive provision costs money now, and how many times have we seen in the past where passive provision is made and it never (never) happens or things get changed in the interim period?  Ultimately, there may not be funding available in the first project to think forward like that, and if initially there was, its quite likely that it would be identified as a potential saving during the GRIP^▸ (Guide to Railway Investment Projects - Network Rail's process for project management of schemes through development and implementation) development process and eliminated from the scope accordingly.

I completely agree with that as a general point.  But in Graham's example I am not sure that putting the trunking out of the way a few feet further to the right would have cost any more.