All SD70MACs except for the early BN ones had Isolated Cabs, as did all SD80MACs and SD90MACs (both 4300hp and 6000hp). In DC motored locomotives Conrail's last two orders of SD60s have the Isolated Cab, all of CN's SD70 and SD75 locomotives have it (except the SD70s built for the IC), and the SD75s ordered by BNSF have it. The AT&SF never bought any, and none of UP's SD70Ms have it.
The recent revival of the Isolated Cab is due to tighter FRA requirements for noise levels in the locomotive cab. The first SD70ACe locomotives built with the Isolated Cab were the second order for BHP Billiton, the Australian iron ore railroad.
Alaska Railfanning / My ARR Photos on Flickr
trainfan1221 wrote:If I recall the isolated cab originated on Conrail with an order of what would have been SD60Ms, but were the first to receive this cab and thus dubbed SD60Is. They looked pretty much the same.
The first one was CR 5544, the first SD60I. It was the last unit in an order of SD60Ms. The goal was to get the cab noise level down below 80dB, which it did.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Our (CSX) 70ACe's are very rough riding and extremely loud. I have to wear earplugs when ever I'm in them. They were assigned to the B&A freight trains for a time, and every time I worked I hoped that one of them was'nt the leader. I can't stand them. Now we get the 6000 HP GE on the freight trains.
To be fair, the ACe's do seem to pull well. Several times I've had two of them on 8500 ton trains pull up the mountain at 2 MPH, with wet rail, without stalling. The GE's would likely stall in the same conditions.
There is a max length and tonnage rule for van trains, but not for freight. The vans can't exceed 10,000 feet or 9,000 tons and that rule is followed to the letter.
Freights are more go with what is known to work. The 70 ACe's and MAC's are known to pull well so they will go with two of them on an 8,500 ton train. The GE 6,000 HP engines will pull to, and faster as long as the rail is dry. They are slippery when the rail is wet.
There is a reason why you almost never see a set of the new ES4400DC's heading a heavy freight on the B&A. They don't work well on the B&A in that service.
Last year, they were trying to pull 10,000 tons with the new 700 series ES4400AC's, and it did'nt work out to well. Lots of stalled trains.
Lyon_Wonder wrote:According to my Kalmbach diesel guide book, BN and BNSF SD70MACs 9400 through 9571 had regular wide cabs. 9572 and onwards have the isolated cab with the visible separation line on the nose. The book claims that all SD70MACs produced March 1995 and later have isolated cabs. I know this applies to all BN/BNSF MACs, but did any other railroads order any later phase MACs without the isolated cab. I know that ARR and CSX/ex-Conrail have MACs. UP ordered a large number of non-AC SD70M's that don't have isolated cabs either. What makes this question precarious is when EMD came out with the SD70ACe/M-2s that suddenly dropped the isolated cab until recently. Early SD70ACes used by BNSF/KCS/UP and others have a regular, non-isolated cab. I think the first road that ordered SD70ACe’s with the isolated cab was a line is Australia. Now the isolated appears to be a standard feature on SD70ACes, like the SD70MACs before it. Either the railroads asked EMD not to incorporated isolated cabs in their SD70ACes until recently, or EMD had trouble remembering all the features they included with their locomotives:)
The latest series of SD70Ace being delivered to the Union Pacific have the isolated cab. I believe they are getting at least 50 of the new series in the 8620 range. The fourth picture down of the 8639 is one of the new ones with the low nose headlight and isolated cab.
http://forums.railfan.net/forums.cgi?board=UP;action=display;num=1116099240;start=240
Santa Fe had ordered SD75Is and that order continued into the BNSF era with The BNSF SD75Is. All these SD75Is were painted in the Warbonnet Scheme when delivered to the Santa Fe and BNSF.
Andrew
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Andrew Falconer wrote: Santa Fe had ordered SD75Is and that order continued into the BNSF era with The BNSF SD75Is. All these SD75Is were painted in the Warbonnet Scheme when delivered to the Santa Fe and BNSF.Andrew
I think you're mixing up the "I" and the "M" there. For SD75Ms, Sante Fe had ATSF 200 thru ATSF 250 (which then became BNSF 8200 thru 8250); these were built in early 1995. BNSF had a seperate order and continued that series with BNSF 8251 thru BNSF 8275, built late 1995/early 1996.
BNSF then ordered SD75Is numbered BNSF 8276 thru BNSF 8301, built between Oct-Dec 1997.
From what I've heard, the new Iso cab 70ACe's and 70M-2's are still quite bad noise wise, and dont ride near as well as the GEVO's. The 70MAC's and 75I's are seemingly coming "un glued" too, as they are some of the worst riding "newer" power that the BNSF/CN have. They also rattle like no tomarrow.
Alec
I remembered that ATSF got the SD75Ms and BNSF got the SD75Is a day after I posted.
They were all in the Warbonnet scheme and many can still be seen today.
Andrew Falconer wrote: I remembered that ATSF got the SD75Ms and BNSF got the SD75Is a day after I posted.
Well, you're half right...ATSF got half the SD75Ms...the second order was BNSF.
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BigJim wrote:The CR (now NS) SD60I's are absolutely the quietest cabs that I have ever been on! Period.
You're welcome!
The newer SD70Ace's on the Up are equipped with the Isolated cab, they do ride a little better than the standard cab SD70Ace's I have been on in the past, noise lever has changed a little, a HUGE improvement over the SD70M's noise and vibration (run 8 in an SD70M is brutal). Still though when I look to see what train I am catching I always hope for a GEVO, better riding and very quiet in the cab.
Name witheld at the request of UP management...............
We call them "THUNDERCABS"!
Broadythecableguy
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