Yellow tape arrow on platforms

Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: CRail, sery2831

Yellow tape arrow on platforms

Postby Pete » Thu Sep 17, 2015 6:04 am

Every Red Line platform of late has an "arrow" (really just two 3"-wide pieces of tape mounted at a right angle) pointed a a survey spike with a reference number written alongside. What are these for?
Pete
 
Posts: 308
Joined: Tue Mar 16, 2004 4:53 pm
Location: Boston, USA

Re: Yellow tape arrow on platforms

Postby octr202 » Thu Sep 17, 2015 7:47 am

I've noticed them on the Orange and I think even some Green Line platforms in the last few weeks as well.
Wondering if I'll see the Haverhill double-tracking finished before I retire...
Photo: Melbourne W7 No. 1019 on Route 78, Bridge & Church Streets, Richmond, Victoria. 10/21/2010
User avatar
octr202
 
Posts: 4142
Joined: Fri Mar 12, 2004 8:13 am
Location: In the land of the once and future 73 trackless trolley.

Re: Yellow tape arrow on platforms

Postby Gerry6309 » Thu Sep 17, 2015 9:08 am

octr202 wrote:I've noticed them on the Orange and I think even some Green Line platforms in the last few weeks as well.

I noticed them at the rear ends of Downtown Crossing and Tufts Medical Center yesterday. Could be a stopping point when running wrong-rail.
Gerry. STM/BSRA

The next stop is Washington. Change for Forest Hills Trains on the Winter St. Platform, and Everett Trains on the Summer St. Platform. This is an Ashmont train, change for Braintree at Columbia.
User avatar
Gerry6309
 
Posts: 1484
Joined: Wed Jun 13, 2007 10:46 pm
Location: Boston

Re: Yellow tape arrow on platforms

Postby octr202 » Thu Sep 17, 2015 11:22 am

So far they appear to be at both ends of the platform.
Wondering if I'll see the Haverhill double-tracking finished before I retire...
Photo: Melbourne W7 No. 1019 on Route 78, Bridge & Church Streets, Richmond, Victoria. 10/21/2010
User avatar
octr202
 
Posts: 4142
Joined: Fri Mar 12, 2004 8:13 am
Location: In the land of the once and future 73 trackless trolley.

Re: Yellow tape arrow on platforms

Postby dieciduej » Thu Sep 17, 2015 4:18 pm

I have seen them on both the Orange & Green Lines. I noticed on some of them a small surveying marker at the arrow point, also a number written in yellow.

My guess measuring the property for the real estate agent :P !

JoeD
User avatar
dieciduej
 
Posts: 553
Joined: Tue May 09, 2006 9:37 am

Re: Yellow tape arrow on platforms

Postby BostonUrbEx » Thu Sep 17, 2015 8:27 pm

Gerry6309 wrote:Could be a stopping point when running wrong-rail.


Saw one at the north end of the southbound platform at State today. It lined up with the cab window at the rear of the train. I'm almost inclined to suspect they're installing a screen for running wrong-iron or for short turning. It would certainly be necessary in some cases with some of the ever-so-gently curved platforms downtown.
User avatar
BostonUrbEx
 
Posts: 3603
Joined: Thu Dec 03, 2009 9:55 pm
Location: Winn to MPT 8, Boston to MPN 38, and Hat to Bank

Re: Yellow tape arrow on platforms

Postby diburning » Thu Sep 17, 2015 9:04 pm

I saw one at Central on the red line today, Alewife-bound side.
User avatar
diburning
 
Posts: 2970
Joined: Sat Feb 09, 2008 7:37 pm
Location: Practicing safe CSX by using Three-Step Protection

Re: Yellow tape arrow on platforms

Postby dieciduej » Fri Sep 18, 2015 2:09 am

At the station formerly known as Mechanics!

JoeD
Attachments
Prudential.JPG
User avatar
dieciduej
 
Posts: 553
Joined: Tue May 09, 2006 9:37 am

Re: Yellow tape arrow on platforms

Postby CRail » Fri Sep 18, 2015 12:29 pm

They're systemwide, and not only on platforms.
Moderator: Massachusetts Bay Transportation Authority
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).
User avatar
CRail
 
Posts: 2132
Joined: Tue May 18, 2004 8:27 am
Location: Eastie

Re: Yellow tape arrow on platforms

Postby diburning » Fri Sep 18, 2015 8:45 pm

I saw one at Packard's Corner today as well.
User avatar
diburning
 
Posts: 2970
Joined: Sat Feb 09, 2008 7:37 pm
Location: Practicing safe CSX by using Three-Step Protection

Re: Yellow tape arrow on platforms

Postby StefanW » Mon Sep 21, 2015 5:40 pm

If they are also showing up on Blue Line platforms, that blows my theory that it has to do with measurements for the new cars (Red / Orange and Type 9 Green).

My next-best theory is it has to do with the video surveillance that's been installed at the ends of almost every platform. I have yet to get this confirmed, but as far as I can tell there are cameras at every tunnel entrance and platform end backed by motion-sensing video processing. I believe that's why there is a ID reader PIN-pad with the red LED at every platform end. I'm speculating that if someone enters the tunnel and/or goes beyond the end of the platform the video surveillance would pick them up and alert Transit Police, unless they had signed-in first on that PIN keypad.

If I"m right about that, then the yellow arrow tape markers could be used to calibrate / test the video surveillance.
User avatar
StefanW
 
Posts: 490
Joined: Wed Aug 18, 2004 8:27 pm
Location: Lynn, MA / MP 11.53

Re: Yellow tape arrow on platforms

Postby StefanW » Mon Sep 21, 2015 5:43 pm

StefanW wrote:...the yellow arrow tape markers could be used to calibrate / test the video surveillance.


However if the arrows are also on above-ground stations that blows that theory also... unless there are general-purpose security cameras also above ground...?

Is there any video surveillance at Packard's Corner?
User avatar
StefanW
 
Posts: 490
Joined: Wed Aug 18, 2004 8:27 pm
Location: Lynn, MA / MP 11.53

Re: Yellow tape arrow on platforms

Postby Diverging Route » Mon Sep 21, 2015 7:22 pm

A friend who is an Inspector on Rapid Transit confirms the marks are for a GPS survey that was recently done. Once in the tunnel, he says, they had
a limited time for accurate surveying due to loss of GPS signal.
User avatar
Diverging Route
 
Posts: 1562
Joined: Sat Mar 13, 2004 3:35 pm

Re: Yellow tape arrow on platforms

Postby Yellowspoon » Fri Oct 09, 2015 6:26 pm

Diverging Route wrote:A friend who is an Inspector on Rapid Transit confirms the marks are for a GPS survey that was recently done. Once in the tunnel, he says, they had
a limited time for accurate surveying due to loss of GPS signal.
The markers are reference points for old-fashioned surveying. GPS becomes unusable for surveying the instant you lose direct line-of-sight to GPS satellites.
User avatar
Yellowspoon
 
Posts: 201
Joined: Wed Jun 14, 2006 1:00 pm


Return to Massachusetts Bay Transportation Authority (MBTA)

Who is online

Users browsing this forum: No registered users and 5 guests