SEPTA is in discussions with other transit agencies to possibly borrow equipment to make up for some of the 120 Silverliner V commuter rail passenger cars taken out of service due to a defect in a load bearing component.

Of the agencies, NJ Transit and Amtrak have the most compatible trains and use the same overhead power system.

There is no word yet on what — if anything — the other agencies might be able to provide to make up for the loss of a third of the SEPTA fleet, but there was some speculation that NJ Transit could at least take over some operations between Trenton and 30th Street Street Station.

Currently, NJ Transit trains operating on the Northeast Corridor have their southern terminus in Trenton, where riders must switch to SEPTA or Amtrak for the trip to 30th Street Station.

"We're looking at the options now," NJ Transit spokeswoman Lisa Torbic said in an email. "All of NJ Transit's rail cars would technically be compatible with SEPTA's system. However, multilevel cars would be restricted to staying on Amtrak's Northeast Corridor between Trenton and 30th St. station for compatibility reasons."

In addition, she said, under existing regulations, only NJ Transit crews could operate NJ Transit equipment.

"We are looking at all options which would not strain NJ Transit service, equipment or crews, and ultimately impact our customers," Torbic said.

Amtrak spokesman Mike Tolbert confirmed discussions were underway with SEPTA but no decisions have been made yet about equiment assistance.

In the meantime,  Amtrak will make four more stops at Ardmore - three inbound and one outbound - and add an extra car to six of the eight Keystone trains between New York and Harrisburg.

Passengers will need Amtraks ticket to ride on the trains.

SEPTA also reached out to New York's Metropolitan Transportation Authority, which operates MetroNorth and the Long Island Rail Road.

"We are evaluating the request," said Aaron Donovan, an MTA spokesman.

There is little, however, that the MTA could provide outside of some passenger cars that are pulled by locomotives because most its trains run off third-rail power.

Earlier, on Day 2 of the SEPTA Regional Rail  nightmare, commuters found trains and platforms more crowded much earlier than on Day 1.

At least four trains operating before 7 a.m. were forced to bypass some stations and operate as expresses for part of their journeys. As more commuters headed to work throughout the morning, yet more jammed trains were bypassing stations.

Besides crowding, many trains ran late.

Riders reported commutes that were taking far longer than normal, and said it was frustrating not knowing how long their trips would take in the aftermath of structural deficits that have forced SEPTA to pull a third of its Regional Rail fleet out of service for repairs.

Michael Balduyck of Levittown was on vacation and hadn't heard about the fatigue cracks causing adjusted schedules and delays.

"Was waiting out there for a while. It was pretty packed," he said. "But it's for our safety, so I get it."

SEPTA General Manager Jeff Knueppel had predicted Wednesday would be a "little worse"  than Tuesday as more people returned to work after a long holiday weekend.

The agency's subway lines on Wednesday were also busier than normal, as riders who typically take Regional Rail sought out alternate ways of getting to work.

On Friday, SEPTA officials said they discovered cracks in a key load-bearing component of the Silverliner V's, their newest rail car, that forced the authority to pull all those cars, a third of SEPTA's total rail fleet, from service.

Tuesday was the first day of commuting since the Silverliner V's were taken off the rails. SEPTA normally runs 788 trains a day. Tuesday it ran 560.

The problems could last all summer.

Alice Antonelli, 55, a regular at Ardmore, said she may consider taking the trolley or her bicycle in the future.

"I will say, I'm so glad they caught the problem," said Antonelli, a financial consultant. "It could have been a disaster."

Other riders also said the extra waits were worth it for safety.

"For me, it's just a minor inconvenience," said Julian Baseman, 21, of Newark, Del., as he waited for a train home at Jefferson Station.

SEPTA is offering refunds or credit to people who purchased weekly or monthly passes.