Quote from an article posted in the West Side thread:
http://www.globeinvestor.com/servlet...VER15/GIStory/
West Side Story
SINCLAIR STEWART
December 15, 2007
For several weeks last month, all of these groups were crammed into a small showroom across from Grand Central Station, where the public could inspect their models, talk to company officials and provide commentary in a suggestion box. Brookfield, with some luck, won a coveted spot next to the entrance, and its presentation was arguably the most sophisticated - walls were plastered with images of gleaming glass buildings and families gamboling in green parks.
Yet the slick presentations belie a vexing logistical problem for the builders: pouring foundations and erecting a platform without disrupting the train traffic. Every morning, after disgorging passengers at Penn Station, the trains continue east and park in the yard; at rush hour, they swing back to Penn, pick up travellers, and transport them to Long Island and New Jersey.
The MTA has said it can close just four of the 30 tracks at any one time to facilitate construction, meaning any development effort will require considerable precision.
Most developers, including Brookfield, are pitching a plan that would set foundations in the ground, and use the buildings to help disperse the weight of the platform, which would reach 10 metres above street level at its highest point.
Complicating matters further is the uneven grade of the area, particularly a steep hill that descends from 10th Avenue, which is well above the yards, to the Hudson River, where trains are at street level. The unusual nature of the site has created all kinds of unexpected headaches; merely designing lobbies for Brookfield's office towers here required an enormous amount of engineering work, given that their placement would be directly above a sensitive area of the tracks.
But the company has been grappling with precisely this issue for some time now, given its other development project at 9th Avenue, directly across from the Farley Post Office, a Beaux Arts colossus that is itself slated for redevelopment.
This 9th Avenue site, about 40 per cent the size of yards, may be even more complex, given its placement above a busier portion of underground tracks. Brookfield is hoping to break ground on a platform at this site next year, and will no doubt argue that this puts it in a unique position to develop the adjacent corridor of the Hudson Yards.
"I think one of the advantages that we have over the other four competitors is we've actually spent a couple of years studying how to do exactly this, which is how to build a platform and a structure over an active railway in order to create the site," Mr. Clark said. "We've got a bit of a head start versus our peers in that regard."[