More than one-third of MBTA employees getting pensions retired before the age of 55 and a thousand-plus left in their 40s, according to a Herald review of a massive database that was finally released yesterday after a series of stories that challenged the T retirement board’s refusal to disclose the payouts.

Your tax dollars at work: MBTA pensions

The data — which was released by the T itself and not the MBTA Retirement Fund that oversees the $1.77 billion fund — represents a first look into payouts made public under a law the Legislature pushed through this summer.

A Herald review of the database showed:

• More than half of the 6,300-plus people listed in the database retired before the age of 60, and 35 percent — or 2,240 — left before 55.

• Another 1,129 retirees, or 17 percent of the system, opted out in their 40s. They include five of the top 30 pension holders, including former MBTA General Manager and the fund’s current Executive Director Michael Mulhern, who retired at age 46 with a pension of $64,800.

• Eight retirees are pulling in more than $70,000 annually, with the top earner at $76,881. All of them retired before the age of 60.

Demands for scrutiny have stepped up as taxpayers have been forced to funnel more to cover T pensions. Those payments soared to $56.3 million last fiscal year, up from $30 million in fiscal 2007.

“I think it’s safe to say, when I hear some people with a full boat in their 40s, that raises some eyebrows, and that is precisely the reason we wanted to take a look at some of these documents to make sure the tax dollars are being spent correctly,” Rep. Brad Hill (R-Ipswich) said.

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Currently, T employees can retire with a pension at 55 with 25 years of service in the transit agency, according to the T. But many retired under previous guidelines, where they were able to punch out at any age if they accrued 23 years of service.

While the individual payouts released yesterday may not reach the staggering sums of other pension systems — the state, for example, has at least five people getting over $200,000 — the old T rules allowed many to retire earlier.

“That’s a very generous pension that you can get after only 20 (plus) years of service,” said David Tuerck of Suffolk University’s Beacon Hill Institute.

The data’s release comes after a series of Herald reports about the retirement fund’s foot-dragging response to the paper’s public records request. That request was sent right after the law requiring public disclosure of the database was enacted on July 12.

The pension fund’s stonewalling sparked a growing chorus of criticism, including from Secretary of Transportation Richard Davey and, just yesterday, Speaker of the House Robert A. DeLeo, who said he was “frustrated” with the panel’s response — just hours before the pensions were disclosed.

“You guys are probably the ones who made it happen,” said Paul Regan, executive director of the T advisory board, citing a Herald story yesterday in which Davey said the board “need(s) to be compliant.”

“The MBTA received the pension data about two hours before the Herald received it,” T spokesman Joe Pesaturo said in an email. “It was released for the very reasons described (Wednesday) by Secretary Davey. MassDOT and the MBTA are strongly committed to openness and transparency.”

Steve Crawford, a spokesman for the retirement board, declined to comment, instead pointing to a three-page response the panel’s lawyer sent to the Herald this week.