I've been to Seattle three times in the last few years visiting relatives that live over there. Always found it to be a pleasant city, but with some bad spots like any where.
I didn't think were supposed to work in tunnels or if its possible for them to do so. Obviously the others must be programmed back to back or something from the sound of it. They still have working guns though, so I wouldn't be too worried!
The Seattle system and the King County/Valley Com systems are different.
At least they were when I worked for King County. (I'm retired from there)
Both systems shared some "resources" tho.
Some special assignment people have their radios programmed to be "native" on either system.
Probably both systems SHOULD have been the same system.
Maybe that is the direction they will go.
Last time I worked details in the tunnel, my radio worked fine on KC/VC, but I never spent much time down there.
And, some of the infrastructure is getting old now.
As one of the above posted, likely they are looking for funding.
Unless there has been major changes, I think a lot of that system is maybe a dozen years old.
And, after working for KC for nearly 30 years, I know they OFTEN have trouble funding things.
"Seattle's police radios were never designed to work in the concrete confines of the tunnel"
End of discussion lol.
They answered their own question.
A more more cost effective solution may be a PROPERLY ENGINEERED bi-directional amplifier (BDA) system . The key is to be properly engineered, for the right signal levels to avoid the unit oscillating into itself (hearing itself).
A good BDA will run you $10,000 + right off the start. Then labor for hardline and antenna installation. The BDA will also need to be a on a generator circuit as well as having a quality UPS. They are not a $100 fix, but they are a good proper way of providing signal to a small area that needs coverage.
A BDA will be a more simple solution then making system changes. We have used them in tunnel systems with excellent results.
You need a BDA for the band you want to cover. So if you want VHF/UHF and 800, then you need three BDA systems....one for each band.
I know Los Angeles has the same problem. A couple of the old analog Sheriff channels work underground but the LAPD system is completely useless. Just like with Seattle the LASO has jurisdiction over underground but if for example an LAPD officer chases someone and they run into the subway system they have no way to communicate once their underground. BART in the bay area though they're on EDACS do have underground repeaters so it would be possible to resolve the problem and hopefully for Seattle and others that have this problem the situation will finally make them do something about it.