Placing bridges at the start and end of tunnels (around / in tunnel exits)

Topic: Placing bridges at the start and end of tunnels (around / in tunnel exits) (Read 22500 times) previous topic - next topic

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #35 – January 19, 2009, 06:54:58 pm

I am not sure I understand?

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #36 – January 19, 2009, 07:24:14 pm

Quote from: VS – on January 19, 2009, 06:54:58 pm

I am not sure I understand?

Ok, maybe only tunnel entrances visible from the surface and not necessarily whole tunnels...

Is it better explained, or still not quite...? $:-\$

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #37 – January 19, 2009, 07:44:26 pm

You want:

a) picture
b) something added to game
c) something added to pak
d)

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #38 – January 19, 2009, 07:57:40 pm

Quote from: VS – on January 19, 2009, 05:33:54 pm

You want something that is not possible (at the moment at least) so you are given some choices how to do it otherwise...

Allright.

Picture for now (because of what you told me in the above quote). $:-\$

Then b) and/or c), if still possible... $:-\$

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #39 – January 19, 2009, 08:53:26 pm

You seek a solution of a very unreal situation. And not only in Simutrans and the real World.
The attached solution shows the unreality.
There is not existing any road/railway ending just at the water-level of the coast.

In the same way you can create a Simutrans world full of psychedelic constructions,
like this one:

[attachment deleted by admin]

Re: Placing bridges at the start and end of tunnels (around / in tunnel exits)

Reply #40 – January 19, 2009, 09:49:53 pm

The only thing I can think of is that Simutrans makes a presumption that all bridges have clearance for ships beneath. Yet in reality railway bridges across harbours or estuaries clearly do not provide this clearance. That clearance is the reason the tunnel can exit at "sea level" but the bridge needs a +1 ramp before its span starts.

In reality, low-level water crossings incorporate a swing span or lift span to provide that clearance. - only rarely do they climb to the spectacular heights necessary to provide the clearance reqiured by the Admiralty or similar for ocean-going ships to p**** beneath.

E.g Barmouth Bridge does not provide clearance for ships.

Whereas the Royal Albert Bridge at Saltash is rather spectacular specifically because it was required to provide that clearance for ships.

If we cross a rail line over a canal on the flat, one of those nifty automatic lift bridges appears. We are able to cross it at water level, and so ensure a clear and level through run for our nice express trains.

My point, then, is simple. Why can we not provide an equivalent "flat" alternative for crossings over wider bodies of water? With a "lift" span appearing in the middle? A bridge which deliberately obstructs shipping except for that opening span.

To be clear about how close to the water I mean, there is a partly demolished one near my home. The timber trestles have gone but the photographer is standing on the former trackbed. Pivot for swing span is in the distance. [EDIT - This example is near Portsmouth harbour (map)]

Given the parallel conversation about rivers I think this has a bearing. I said over there the rivers should not require "hump back railway bridges" - this is the realistic solution. It's applicability to coastal situations (tunnels at sea level) is more niche. I've put the remark here because it follows neatly though.