NW2 vs. SW7

Model Railroader General Discussion (Model Railroader)
1

I have a switcher shortage on my layout and I want to get one of the BLIs in C&O paint. But what is the difference between an NW2 and an SW7?

2

I’m not sure of the difference but, I just bought the NW2 in BN livery and it’s great! It runs smooth, slow, and has good pull. The sound, of course, is top notch.
Just my $0.03
BB

3

I know that the NW units are rated for 900 horse power and the SW units are rated for 600 horse power.

I know that the W in NW or SW stands for welded frame nad if it is an SC or NC its a cast frame.

Thats what I know.

4

The big difference is whether you are doing a specific time period. e.g.: I am doing '47-'50 GN and the '7’s came out around '54, so i will stick with the NW2 which I am trying to get but seems in short supply.

5

Joe,

Here is the difference:

NW2 - Was introduced in 1939(or close to it). First production 1000 hp switcher using the new ‘567’ powerplant. Was kept in production through 1949, and was replaced by the SW7. Spotting features are the 1/2 size radiator grill on the front and large ‘curved’ glass windows on the ends of the cab. Eary models have a ‘two step’ taper on the long hood in front of the cab. The BLI model is a ‘late’ NW2 with a ‘single’ taper in front of the cab.

SW7 - Follow-on to the NW2, stayed in production until 1954(replaced by the SW9). This model used a newer model of the ‘567’ engine and sported 1200 hp. Spotting features are a ‘full size’ radiator grill on the front, rather than the ‘1/2 size’ grill of the NW2. Also features the ‘single tape’ hood in front of the cab, and smaller ‘square’ windows in the front of the cab.

James,

The SW/NW and SC/NC terms only apply to the older ‘Winton’ 201-A powered engines(late 30’s) and the SW1 & NW2-3-5 engines. By 1949, EMD dropped the HP based clasification and everything became a ‘SW’(for switcher). The basic ‘wasp waist’ carbody would become an EMD icon for years…

Jim Bernier

6

Jim,

Nice and clear, thanks.

7

Also the windows on the cab of an NW2 are rounded to the cab on the back side and on the SW7 there straight none rounded windows and yes they do have different horsepowers. thats probably the biggest difference.
James

8

Jim you’re close here. The late NW2 and SW7s both used the 12V-567A engine. The change to the 12V-567B came with the SW9s. The SW7 was produced from 10/49 to 1/51 with 493 units built, all in the U. S. The switch to squared windows started with SW7s built 4/50 or later. This is the Phase 2 SW7 model produced by BLI. The Phase 1 SW7 unit has the curved windows that follow the roof of the cab. Diesel data from The Second Diesel Spotter’s Guide. [8)]

9

Thanks for all the responses!

I model modern era, but Im going to weather this as if its something CSX got in the takeover and never felt it important enough to repaint or anything. So it sounds like maybe I want the SW7.