Tiffy Posted April 30, 2017 Share Posted April 30, 2017 Hi All, I am hoping that someone can help me with a small mystery (to me) I have just returned from a weekend away at Dawlish - staying at the Blenheim - right on the sea-front. As you can imagine, I managed to get some pretty good photos during the high winds this morning - but trains seemed pretty thin on the ground, and many of them, did not seem to match up with Real-time Trains very well - which I assume is in part down to the weather (most of the trains were travelling quite slowly through the waves!) Later, we moved over to Teignmouth, to have lunch at The Ness. The view from this excellent inn, is straight across the sea-front at Teignmouth, across to Parson's Tunnel, allowing one to view the whole sea-wall section, and despite a lot of spume in the air, it was possible to make out the trains on the sea-wall over there (about a mile away). I noted a set of white lights leaving the tunnel, which from my distance looked to be a 143 / 150 type DMU combination - but before this train had reached the curve by the skew bridge, another train had exited the tunnel and was following what looked like closely behind - once again a 143/150 type of DMU, and both of these seemed to be travelling at a fair speed - not slowly. I had both sets of front marker lights in view together. Even allowing for the distance / foreshortening effect, these seemed to be awfully close together, and did not look at all right to me. Can anyone shed any light on how these two trains could be passed so closely following, as it is still a bit of a mystery to me. Link to comment Share on other sites More sharing options...
Nearholmer Posted April 30, 2017 Share Posted April 30, 2017 Are both roads signalled bi-di, so that they can run as far from the sea as possible when things are really bad? In other words, were the trains on parallel tracks? K Link to comment Share on other sites More sharing options...
Tiffy Posted April 30, 2017 Author Share Posted April 30, 2017 Are both roads signalled bi-di, so that they can run as far from the sea as possible when things are really bad? In other words, were the trains on parallel tracks? K To be honest, from the distance I was viewing, that is not something that I could discern, but it would certainly explain why the two trains seemed to be so close behind one another. Does anyone actually know if this is the case - I believe Captain K has had some dealings in this locale - I finally got to view the results of his team's sterling work first hand during my visit. Hardly seems believable that it was three years ago . . . . Link to comment Share on other sites More sharing options...
Tiffy Posted April 30, 2017 Author Share Posted April 30, 2017 Are they also permissive block working if they are very close together I was under the impression, probably wrongly, that that would entail slower running, and these seemed to be running at just about line speed for the type. Link to comment Share on other sites More sharing options...
RMweb Premium Kris Posted April 30, 2017 RMweb Premium Share Posted April 30, 2017 From the sound of it they were running on parallel lines. Link to comment Share on other sites More sharing options...
Nearholmer Posted April 30, 2017 Share Posted April 30, 2017 Unless rules changed recently, permissive block can't be used for trains carrying passengers ..... it is usually applied to freight or ecs lines only. If you want to see passenger trains almost nose-to-tail, other than on a tramway, look at a line that has full automation under train-based signalling, several underground lines and the DLR, for instance. When travelling at low speeds, the trains can get eerily close to one another. Conventional, fixed block, systems do sometimes have provision to draw a train up to one already stationary, often to allow portions to couple, but other than that they are separated by whatever the block length is. Maybe that section just has oodles of signals close together? Here is the RSSB guidance https://www.rssb.co.uk/rgs/standards/GKGN0644%20Iss%202.pdf K Link to comment Share on other sites More sharing options...
RMweb Gold TheSignalEngineer Posted April 30, 2017 RMweb Gold Share Posted April 30, 2017 See this thread for previous discussion, including some information from the good Captain. http://www.rmweb.co.uk/community/index.php?/topic/94197-dawlish-warren-newton/ Link to comment Share on other sites More sharing options...
Tiffy Posted April 30, 2017 Author Share Posted April 30, 2017 A big thank you to all who replied - once again the team comes up with the answer. Is there anything that RM-webbers cannot do? Tiffy out Link to comment Share on other sites More sharing options...
stadman Posted May 1, 2017 Share Posted May 1, 2017 Signal spacing on the down is close enough for trains to be in quick succession. Only the up is bi-directional. Link to comment Share on other sites More sharing options...
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