Just in case you ask yourself if multiple Proto 1000 RDC can handle an 18" curve.
Yes they can. Push and pull works fine. The bodies do not touch. Couplers are standard Kadee whisker couplers. The right RDC has the drive shaft in place and the left RDC became a dummy.

Just don't look and listen. The drive becomes quite noisy and it looks like .... but it is valid solution off the scenery part

IMG_5120 by faraway52, on Flickr

That's pushing them to the limit!

Well that answers the question of my hidden 19" radius curve. I wonder how the upcoming Rapido versions would do?

An alternative solution to the problem of the 18" curve may be this <!-- m --><a class="postlink" href="http://www.rmweb.co.uk/community/index.php?/topic/114096-the-cut-down-half-pint-budd-railcar/">http://www.rmweb.co.uk/community/index. ... d-railcar/</a><!-- m -->

shortliner Wrote:An alternative solution to the problem of the 18" curve may be this <!-- m --><a class="postlink" href="http://www.rmweb.co.uk/community/index.php?/topic/114096-the-cut-down-half-pint-budd-railcar/">http://www.rmweb.co.uk/community/index. ... d-railcar/</a><!-- m -->

MSTL had an RDC 4. http://www.rrpicturearchives.net/showPic...id=2347308
I have a kit bashed model of that short RDC. That old model in the basement was the trigger last week to look after standard length RDCs on my layout.

Good news!

I got a new RDC 1 today. The "new" RDC has an 8pin DCC plug and can be easy identified by the black painted chassis and trucks while the "old" ones are silver. That "new" RDC negotiates my 18" curve with very little noises. It runs just fine on my layout (still don't look at it negotiating 18" curves, you risk a stomachache hock: )
The color is a bit different. The old ones (front and rear) are silver with a little yellow shadow. The new one in the middle is silver with a black shadow.

IMG_5146 by faraway52, on Flickr

Ouch that is a painful curve. I'd almost suggest MP54s (the Long Island RR type run on third rails so you don't need catenary). They'll definitely get around your tight curves without looking too crazy.

It never occurred to me to even try to run my RDCs (or even most of my 85' MU cars) on anything much less than 22". Thats usually asking for trouble.

I have a pair of the Rapido RDC-1s in Reading Company on order, I wonder if they can squeeze into these curves?

Green_Elite_Cab Wrote:.....
I have a pair of the Rapido RDC-1s in Reading Company on order, I wonder if they can squeeze into these curves?

I bet they can. The old ones with a nasty noise and the new ones with a quite nice noise. But keep your eyes closed!
I am running three RDCs together is regular schedule since two days.