Jeff might be able to fill in the details on this a little better, but the Superliner substitution on trains 510/517 was planned long before the problem with the Talgos surfaced. All of the Talgos were scheduled to rotate through CEECo this year for refurbishment, and since there are no extra sets available, it was decided to cover the Vancouver train with Superliners to take a Talgo out of the normal VAC-SEA-PDX-EUG rotation. That's why there was no problem keeping 510/517 running when the Talgo problem did appear. Originally, the train ran with two coaches and a lounge car, but for some reason (I've heard mechanical), the lounge has been replaced with another coach equipped with a snack bar downstairs. Unfortunately, this never made it into the Amtrak computer and the train can be "sold out" even though there are plenty of empty seats in the third coach. However, the Superliners ride much nicer going through White Rock than the Talgos ever did. I feel this may be because the Talgos are built for high-speed and their suspension doesn't handle the track up north too well. I've also heard from some sources at Amtrak that feel this may be the cause of the current Talgo malady, but there is no proof to back this claim.

In regards to pulling the Talgos from service, it was the safe move to make. Until you know exactly what you're dealing with, you don't want to take a chance on one of the arms breaking under stress -- say doing 79MPH with a full load of people.

Also, the Talgos are authorized to run at higher speeds than regular passenger trains between Vancouver BC and Portland, although not higher than the maximum 79MPH allowed by the FRA. Because of their tilting ability, they have higher speed limits through curves than standard equipment, which helps maintain a faster end to end schedule than the substitutes. It also makes for some interesting speed limit signs (there's one in Tacoma that reads 67MPH).

Ken