Intertrack Fencing Construction and Maintenance

Transcription

1 Panel Discussion On Intertrack Fencing Construction and Maintenance Tuesday, September 22, 2009 Passenger & Transit Session 9:30AM to 10:00AM. Facilitators: D. Grigg, C.E.T., PMP Hatch Mott MacDonald J. Lorenzini, P.E., MBA Metra

2 Introduction Purpose Of Intertrack Fencing: Track safety Prevents rail commuters/passengers from crossing multiple tracks between station platforms

3 Typical Configurations: Chain link or metal post and mesh Extends full length of platform and often 100 to 200 ft beyond either end Often includes 1 or 2 maintenance access gates Located at the ½ way point between track centres Top of fence 4 ft or less above top of rail

4 Types of Fencing: Fixed with posts embedded in concrete foundations No flexibility for dimensional loads or track maintenance machines (eg. tie change out)

5 Types of Fencing: Ornamental Fixed either bolted or embedded to/in concrete foundations No flexibility for dimensional loads or track maintenance machines (eg. tie change out)

6 Types of Fencing: Knock-down mounted on concrete foundations Accommodates dimensional i loads and track maintenance machines

7 Types of Fencing: Metra s new removable fencing

8 Types of Fencing: Sometimes a combination of 2 different standards Knock-down and fixed chain link

9 Types of Access Gates: Hinged, swing

10 Access Gates: Horizontal, rolling panel

11 Pedestrian Accesses: Limits access across tracks to specific, controlled locations

12 Constructability Issues: Removal of existing fences Removal of old fence for entire length of platform prior to installation of new fence Risks: No physical barrier to prevent track crossings Mitigation: Temporary construction (snow) fencing can be used to fill gaps needs to be secure to prevent clearance restrictions

13 Constructability Issues: Removal of existing fences Construction fencing as temporary intertrack barrier Can be further secured by installing 2 x 4 top rail lbetween T-posts

14 Constructability Issues: Removal of existing fences Old fence post foundations can be left in place to avoid disturbing adjacent track beds

15 Constructability Issues: Construction access to devil-strip Installation of a plank crossing avoids risk of construction equipment getting hung up on rails (eg. bobcats) Also avoids construction equipment tire damage (eg. backhoes)

16 Constructability Issues: Track protection Recommended: Rule 42 or equivalent provides most positive form of track protection Flagman controls both adjacent tracks by both flags and radio control Allows flagman ability to shut down contractor operations on approach of train traffic In the event of an emergency (eg. equipment fouling track), train can be stopped until equipment cleared

17 Constructability Issues: Clearance restrictions Temporary and permanent clearance dimensions need to be checked and monitored on a regular basis to ensure dynamic operating envelope does not become restricted

18 Clearance Constraints:

19 Maintenance Issues: Vegetation control, including small tree growth, in vicinity of fencing can be problematic to remove

20 Maintenance Issues: Frost heave can create restricted vertical clearances

21 Discussion Lessons Learned

22 Thank you for participating Acknowledgements: Photos courtesy of GO Transit, Toronto, Ontario, Canada and Metra, Chicago, Illinois