These models all share the same chassis / mechanism. And apart from minor variations in detailing, share very similar shells as well. These were the first Atlas diesels to feature MU cables on the pilots and amber beacons on the cabs.
The mechanism sports all the features one normally associates with "modern" Atlas diesels - IE, split-frame / all-metal chassis, 5-pole / skew-wound "scale speed" motor with dual flywheels, low-friction drive, bi-directional "white" LED lighting, all-wheel drive and pickup (no traction tires), blackened / low-profile wheels, shell-mounted Accumate couplers, all-plastic gearing, etc. The chassis is fully DCC-Ready (and, in fact, available with factory-installed decoders).
Performance on these models is perfect in every way - smooth, quiet, flawless pickup and throttle response, exceptional pulling power, etc.
One issue that has come up with these models (particularly the Dash 8-40BW's) is that some of them, as delivered, make just one hell of a lot of noise (manifesting itself as a combo platter of buzzing and screeching sounds). I had one of the noisy buggers myself and addressed the problem by taking it apart and lubricating the worms, bearing blocks and driveshaft cups. Once properly lubed, it ran just as smoothly and quietly as any of my other Atlas diesels. A bit odd for an Atlas, though. Normally, such heroic measures (vis'a'vis lubrication) are not required.
Prototype information (DASH 8-40B) -
Built in the late 1980's by GE, the DASH 8-40B diesel locomotives were identified by their dynamic brake gear located along the roof line between the cab and engine compartment, with ventilation provided by large roof-top grilles. These four-axle, high horsepower engines are still in service today in North America.
Prototype information (DASH 8-40BW / DASH 8-32BHW) -
Designed by GE in the late 1980's for Santa Fe as part of their "super fleet" of locos, the four-axle, high horsepower DASH 8-40BW is still in service today. Amtrak liked the design so much, they had the DASH 8-40BW modified to reflect their new generation of passenger diesels to a DASH 8-32BHW.
Shell removal is very simple - just take hold of the shell with one hand and the fuel tank with the other. Then just wiggle the shell up and off.
Grade: A (for all)
Dash 8-40B reviewed: 08/02 Model Railroader ("Atlas has released an N scale GE Dash 8-40B road diesel locomotive and it's a beautifully detailed, fine-running model. From the exquisitely rendered MU cables on the front and rear pilots to the amber warning beacon atop the cab, this Dash 8-40B sets a high standard by which all other N scale diesels are likely to be judged... I easily removed the body shell by grasping it with a thumb and forefinger just aft of the cab and gently pulled upward whole holding the fuel tank. Inside this all-new model, which is made in China, is a split, cast zinc alloy frame. The five-pole, skew-wound, double-ended motor is isolated except for the brush holder tabs. Power from the rails is conducted from the chemically darkened wheels through brass bearing wipers contacting the axle ends. Springy phosphor bronze pickups inserted into the frame contact metal tabs atop the wipers and energize the frame halves. Turned-brass flywheels smooth out the motion to the drive train, which is made of plastic and metal parts. A brass worm over each truck drives the wheels through plastic gears in the trucks. The wheels meet NMRA standards for gauge and flange depth, and the body-mounted Accumate knuckle couplers are at the correct height.
"Atlas is offering this model with or without a factory-installed Lenz decoder. Locomotives without decoders can be converted to DCC by simply replacing the lighting circuit board... Our samples closely match prototype drawings... Like Atlas' previous B23-7 and B30-7 locomotives, the Dash 8-40B features painted handrails, numbers in the number boards, a snowplow, and cab sunshades. The brake wheel, exhaust hatch, handrails, and three-chime horn are separate parts. The body shell and walkway are superbly molded with sharp definition - including a silhouette of the radiator fan - and the plastic trucks have good relief detail. Paint and lettering on our samples were generally crisp and opaque, with numerous tiny warning labels... The model features Atlas' new slower-speed motor, which it introduced last year with the GP38. Our sample started smoothly and performed well throughout its speed range. During testing, the locomotive drew so little current that the needle on our ammeter barely budged! Most operators will find the usable speed range is between 1.5 and 7 volts. The drawbar pull of .64 ounces will be good for about 15 freight cars. So far in 2002 N scalers have had a lot to cheer about in regard to new locomotives, and this new Dash 8-40B is rightfully garnering a good share of the plaudits. $94.95 (no decoder) or $129.95 (with decoder). AT&SF, BNSF, Conrail, CSX, LMX, NS, SLSW, Susq, UP, Undec")
Dash 8-32BWH / Dash 8-40BW reviewed 02/03 Model Railroader ("Atlas has added a pair of GE modern road diesel locomotives to its N scale line. The Dash 8-32BWH is an Amtrak passenger unit while the similar Dash 8-40BW is a freight locomotive. Both have North American wide-nose safety cabs and share many mechanism parts with Atlas' Dash 8-40B freight locomotive... Both models match the dimensions in GE specifications right down to their different wheelbases... Both models come assembled ad ready-to-run. The body shells are made up of about a dozen pieces which are neatly held together with a variety of concealed latches. Freestanding details like the brakewheel, handrails, MU cables, and snowplow are separate pieces which come factory assembled. Clear glazing fits into the cab window openings to provide the proper setbacks from the exterior walls. The models also share a mechanism that follows the common N scale split-frame design. A PC board carrying the components for either directional constant lighting or DCC is mounted across the top. LED's at each end of the board deliver illumination for the headlights. The balance of the running gear follows the same design as the Dash 8-40B, including a cast zinc-alloy frame, a can motor, turned brass flywheels, and GE's FB-type "floating bolster" trucks... Accumate magnetic knuckle couplers are mounted at the proper height in boxes attached to the metal chassis with small screws... Samples started easily and ran smoothly... Both models drew such low amounts of current that it was hard to discern their draws on our meter. The drawbar pull is equivalent to 15 freight cars... Modern era N scalers will enjoy these smooth running and distinctive GE road locomotives... Amtrak, AT&SF, BNSF $99.95 (or $129.95 with decoder)")