Anyone have experience doing structural site surveys for subway systems?

[DCStructures]

Considering taking on this work. Interested to hear feedback. Thanks.

 

[dik]

Been involved with a few tunnels and mines... also one large, multi-structured hatchery. With the above projects, we've used LiDAR mapping and once we got the hiccups out, it worked fairly well. You may consider that for your site surveying.

Should have mentioned that some outfits use drones with LiDAR; that was used for the hatchery project and we had some hiccups related to fixed reference points and more data 'than you can shake a stick at'.

Dik

 

[hokie66]

By structural, do you mean dilapidation surveys of structures along the route of the subway?

 

[MotorCity]

I would be concerned as to whether or not the subway would be in service during your survey. Good luck trying to pull a tape measure or take laser measurements during the early morning rush in a New York subway.

 

[dhengr]

DCStructures:
Figure out how to do your work around and stay away from the third rail and overhead catenaries. They have some special structures and systems peculiar to that transit system. Understand which of those you are going to be involved in evaluating, and then learn a bunch about them. Understand the constant communication with the transit authority as relates scheduling your work and their train schedules. They have many different work trains and types of work cars, can you commandeer part of a work crew and the right work train makeup to help you, they know the system and schedules and communicate directly with main operations office, and they push you down the rail line, under your stop/go instructions, to do a good share of your inspections. Then you may have to go back to specific locations for some specific details. They have work flatcars, your main work/inspection platform with light/electric generator, your tool chests, measurement tooling mounting base, etc.; they have cars specifically built for inspecting and working on tunnel roofs and overhead catenary wires and structures. I designed and built some of this railcar equip. over the years. I would say that if you are new at this work, I would talk at length with them about what of these types of options are available to you, or how they expect you to do your work. They may not even allow you on the property without a couple of minders, at all times. This is all to be scheduled, and they quit at 4:30, and that means they are back in to office, not stopping field work at that hour, it is all very bureaucratic. They have some kinds of strange engineering thinking; if it has worked for the last hundred years, let’s keep doing it/using it, we know it works. Latest codes, what new codes, new is not always better, it is unproven on our system, therefore no good. Their contracts, specs. and the like are very complex and convoluted, often contradictory; reporting, documenting and paper work can take a great deal of your time, so don’t underestimate that, all to cover their ass.

 

[chicopee]

I took college courses on descriptive geometry and surveying back in the early 60's and these two programs had sections on mining layout and survey. These two courses may be beneficial if you undertake the work.