Norwich — Representatives from six firms attended Tuesday's mandatory tour of the Norwich ice rink, making them the only eligible bidders in the city's request for proposals for a potential rink management firm.

Bids submitted by firms interested in taking over all operations at the city-owned financially struggling rink will be opened at 3 p.m. May 7.

After greeting city Purchasing Agent William Block in the lobby, the representatives scattered to examine the rink's ice, office, kitchen behind the concession stand and mechanical systems.

The City Council held a two-hour public hearing Monday on a controversial ordinance that calls for spending $680,000 to replace the rink's cooling system and upgrade other equipment. The council voted 4-3 to delay a vote until May 19.

Former Hartford Whaler Bob Crawford, who owns ice rinks in Cromwell, Bolton and Simsbury, said he already was familiar with the Norwich rink and its director of operations, Doug Roberts. Crawford said his kids skated and played hockey at the Norwich rink.

"We're looking to see if the ice rink is viable in this area," Crawford said. "I expect it is."

He said he anticipates submitting a bid May 7.

The bid request for a management firm calls for the firm to take over all daily operations and to pay the city either a minimum of $75,000 or 10 percent of the gross revenues from all ice programs as well as the concessions stand, pro shop and vending machines.

The contract still would call for the city to pay for major capital expenses with approval by the Ice Arena Authority.

An alternative bid proposal would allow a firm to negotiate a longer lease period if that firm agrees to take on all capital repair costs — including the cooling system replacement — along with routine maintenance.

The financially struggling rink has operated at a deficit since it opened nearly 20 years ago, and if the council approves the cooling system replacement, the total debt owed to the city would exceed $1 million.

Major problems erupted in February 2013, when the ammonia-based chiller malfunctioned and caused an ammonia leak that forced evacuation of the rink. Temporary repairs were made, but another catastrophic failure occurred May 6, shuttering the rink until a temporary outdoor chiller unit was installed in early November.

The outdoor temporary unit has been very expensive, costing about $1,000 per day with rental costs and inflated utilities usage.

The proposed new cooling system would not use ammonia as a coolant.

In addition to Crawford, firms represented Tuesday were Wonderland of Ice of Bridgeport, Rink Management Solutions of Hamden, FMC Ice Sports of Pembroke, Mass., Ice Management Group of Stamford, and Crew 538 LLC of Lisbon, a firm that specializes in theatrical and special events lighting and staging.

c.bessette@theday.com