Manhattan West, on deck

It’s come down to the nuts and bolts of keeping the trains running to get Brookfield Office Properties’ long-aborning Manhattan West project off the ground.

To build a platform over the sunken West Side rail yard between Ninth and Tenth avenues, Brookfield needs only an agreement with Amtrak, which controls the tracks through the exposed yard 65 feet below its West 31st and 33rd street boundaries.

Last week, Brookfield CEO Ric Clark told us work on the deck would start this spring. Brookfield owns both the rail yard land and development rights above it. But Amtrak needs to ensure smooth operation of trains along its right of way.

Amtrak was guarded about its discussions with the developer, which is itching to launch Manhattan West — a 5-acre, multibillion-dollar commercial project with up to 5 million square feet of offices in three towers atop 200,000 square feet of retail.

“Negotiations are progressing” was all Amtrak spokesman Clifford Cole would say. “We don’t have a certain date for a conclusion but hope to have an agreement shortly.”

Asked to comment on Brookfield officials’ statements to us that the Amtrak talks were “95 percent there,” Cole said, “That’s their assessment. But there are remaining issues, some substantive.”

Welcome to the city’s Most Misunderstood Deck Over a Rail Yard.

Related’s Hudson Yards and Brookfield’s much smaller Manhattan West — which is east of Hudson Yards — may blur in the public mind. But there’s this fundamental difference between them:

Where Related is poised to build an office tower without a platform, Brookfield is set to build a platform without an office tower.

Related’s first planned tower for Coach Inc. would rise on a “terra firma” corner of Related’s 26 acres west of 10th Avenue. It could go up even if a platform were never built.

Brookfield wants to build a deck now and the office buildings later. Brookfield President and Global Chief Investment Officer Dennis Friedrich said, “We’re not building for today, but for 2015-plus” — reasonable in light of a climate in which Wall Street firms, far from expanding, are shedding space.

Manhattan West lies behind a colorfully illustrated fence on the west side of the double-length Ninth Avenue block. The tracks disappear below 450 W. 33rd St., the hulking office building fronting on 10th Avenue, which Brookfield also owns.

Viewed looking east from the roof of 450 W. 33rd St., the rail yard crouches like an imposing impediment to development — although not as imposing as the Hudson Yards tracks, which stretch to the river, look from the roof’s west side.