I was goinng to ask “Ask Trains”, but i thought I’d ask you. Whats the difference between a Dash-8 and Dash-9(Field Marks)? I only see Norfolk and CSX. So far, this drives me nuts[xx(][xx(][xx(][xx(]+[xx(][xx(][xx(][xx(]!!!
Arondak,
There are only a few subtle changes between Dash 8 and Dash 9 units, although on Santa Fe (I know, BNSF) the trucks were different between C40-8 and C44-9 units. The Dash 8s had conventional trucks and Dash 9s had the later Hi-Ad design with coil springs beside the axle boxes. This would apply on NS but I think CSX kept using the old trucks.
Another change was that the air intake was smaller and further back from the cab. This was so they could standardise these parts with the AC4400, which had bigger dynamic brakes, which in all these locomotives was just in front of the main air intake. The air intake is located at the point where the hood drops down to the engine cover, in front of the engine itself.
I hope this is some help!
the differance between a dash 8 and 9 is a high ad design. exsplain this please, also you mentioned bigger dynamic brakes would you elaborate on this also please.
Oh, you lucky person! Being around CSX, which has its 9000 series of GE locomotives, which seem to be neither Dash 8 nor Dash 9 (or both, depending on whom you ask!).
Other than that, a Dash 9 has split cooling (that’s been covered in “Ask Trains”), which makes the radiator “wings” at the rear of the unit thicker from top to bottom.
The trucks remain the best spotting feature. GE’s hi-ad trucks have a sort of flaring by the axle ends that remind me a little of horses’ hooves. These trucks are also under most GE AC4400CWs (again, CSX has a few units that have or had trucks of a different design…GE’s radial trucks, which have been less than successful).
You know, “Ask Trains” wouldn’t be a bad idea…they could run comparative photos there.
Carl
To expand my earlier comments, for Wabash1, the “Hi Ad” stands for high adhesion. These trucks are connected to the locomotive frame directly through pads made from rubber bonded to steel as “Sandwiches”, steel/rubber/steel/rubber (and so on). This reduces the opportunity for the truck to tilt, and reduces the possibility of mainly the lead axle slipping. The standard trucks have similar springs, but they connect to a bolster that connects to a pivot on the frame, in the center of the truck, which allows a little more tilting to take place under load. The dynamic brakes are basically sets of resistors, each with its own electric cooling fan. Because the AC motors can take higher currents as motors, when acting as generators (as they are in dynamic braking) they can produce higher currents and need one extra set of resistors with an extra grille.
A photo on the back of the Kalmbach “Field Guide” shows ATSF -8 and -9 units together, and different views of the same scene are inside.
so you are saying the dash 8 is not a high adhesion engine and the way i am reading this that the dash 9 is a “ac” traction motor engine.?
Yup Wabash he’s right. Also those Hi-Ad trucks are a pain to work on too. You practically have to stand on your head just to change a brake shoe, let alone a traction motor.
P.S. A Dash-9 44CW has DC traction and the AC4400CW is AC.
well I was leading him on to correct hiself but I must say that the dash 8 and dash 9 are considered high adhesion and they are also extended range on dynamic.and they are not ac traction motors they are dc traction motors.
Guys, sorry if I have not been quite clear. What I said (it’s still there) is that GE made the air intake smaller on the AC4400 because of the bigger dynamic installation, and this smaller air intake was used on the DC motor Dash-9s because GE only wanted to make one type of air intake. Pilbara Rail in Australia have enlarged the air intake on their Dash-9s because they operate in a hot desert climate, and new units from GE come with the bigger air intake. In the Dash-9, there is just empty space between the dynamic installation and the air intake, so Pilbara have used this space to make the air intake bigger by adding an extra grille in the space. The radiators are indeed different, as CshaveR, says, but that is harder to tell if you don’t have both types of units together. The air intake size is fairly easy to tell when you are looking at the units alone.
I finally got round to checking my facts in the “Contemporary Diesel Spotter’s Guide” and the “Field Guide to Diesel Locomotives”. There is a particular problem with the CSX 9000 class, which are C44-8, and were built after Dash 9 production started. CSX apparently paint the class C44-9 on them, and they have Dash 9 radiators and steps, but Dash 8 trucks, and a Dash 8 air intake. If GE call them Dash 8, that’s good enough for me! In my earlier posts, I described these as Dash 9 with Dash 8 trucks, which isn’t far wrong. I do understand why Arondak was confused if he only sees CSX and NS units. The photos in the “Field Guide” are good, and the Santa Fe photos, where the air intake is dark on the silver hood are the best guide. I worked this out from my own photos of ATSF units in Cajon Pass, when I got side on photos of a Dash 8 and a Dash 9 together.
Sorry about any extra confusion, but the air intake size is so far still a correct way of telling Dash 8 and Dash 9 apart.
Peter
the easiest way for me to tell them apart is that i have never seen a dash 8 wide body. and ive never seen anything of a dash 9 in a standard cab. In my opinion ( and i may be wrong i have been before) the dash 8 has never been a wide body. now as far as the c44 to me its just a dash 9 only newer.
cn has dash 8’s with the draper taper…carbody
Hey Waba***he UP has Dash-8’s with both standard and wide noses.
never seen a dash 8 in a wide body but i did today did see a dash 9 that was not a wide body. it was standard cab. just correcting myself before i get flamed.
The weird thing is that when NS got their Dash-8’s they were running them long hood front. I’m still trying to figure that one out. Their reasoning behind that was so the crew had better visability of their train. Yeah OK???
the ns did not have the dash 8 as long hood forward. it was a short nose forward. but the ns will run these long hood out. I am not sure where the cut is on long hood front of engine I do know that all the sd70s all dash 8 and 9s are short hood forward. also those unforgettable and now gone c36-7 was long hood forward. so the crew breathed all that soot in. the only thing good about a dash 7 was…well let me think about it maybe i can come up with something.
The Field Guide To Modern Locomotives shows NS C39-8’s # 8633 & 8634 with the long hood designated front . Do they have dual control stands ?? I’ve only seen an NS SD40-2 set up that way.
Conrail has Dash 8s in wide-body cabs, NS has Dash 8s in standard cab, as well as alot of C-39-8s in standard cab. A very easy distinction on the Conrail Dash 8s is the engine numbers on the front are located on the wide cab nose, not above of the windows where they are on all other Dash 8s.
only a few sd40 remain with duel controll stand,
I was goinng to ask “Ask Trains”, but i thought I’d ask you. Whats the difference between a Dash-8 and Dash-9(Field Marks)? I only see Norfolk and CSX. So far, this drives me nuts[xx(][xx(][xx(][xx(]+[xx(][xx(][xx(][xx(]!!!
Arondak,