HO diesel locomotives
Athearn SD40: Full Specifications
Quick answer
The Athearn HO SD40 Santa Fe Locomotive lists at $169.99. Published figures: scale HO, proportion 1:87, wheel arrangement C-C. It suits a DC layout, or a modeller who wants to choose the decoder.
Athearn ready to run at a DC price. The mechanism is the reason to buy it: Athearn drives are smooth and are the easiest in HO to fit a decoder to later.
Every figure below is the manufacturer's own published specification, taken from the product listing and the data sheet. Where a figure is not published it is left out rather than estimated. Price is the listed price when this page was last compiled and it changes often.
Athearn SD40 specifications
The Athearn SD40 publishes scale HO, proportion 1:87, wheel arrangement C-C, at a listed price of $169.99.
| Specification | Published figure |
|---|---|
| Scale | HO |
| Proportion | 1:87 |
| Wheel arrangement | C-C |
Specifications above are the manufacturer published figures, taken from the product listing.
What this model suits on a layout
Best for: a DC layout, or a modeller who wants to choose the decoder.
Category: ho diesel locomotives. The honest test for any purchase in this hobby is whether its numbers match your layout rather than whether it is a good product in the abstract. Work out what your own space, scale and curves actually need first, using the calculators on this site, then check this model against that answer.
The closest alternatives at a similar price
Same category, nearest price. An alternative with no stated reason is filler, so each of these is here because it trades something specific against the model above.
Walthers Mainline EMD GP9 Phase II with ESU Sound and DCC HO Scale
$184.99 Specs and fitmentAn ESU LokSound decoder fitted at the factory, which is the decoder most people would choose to install anyway. Buying it this way is cheaper than the decoder alone.
Best for: anyone who wants ESU sound without doing the installation
Check price on Amazon
Bachmann GP35 TCS DCC Sound Value Equipped Locomotive Great Northern HO Scale
$129.99 Specs and fitmentThe cheapest way into factory DCC sound in HO by a wide margin, using a TCS decoder. Sound Value is a reduced feature set rather than a full sound decoder, and that is the trade.
Best for: sound on a budget, accepting fewer functions
Check price on Amazon
Bachmann SD40-2 DCC Sound Locomotive Union Pacific HO Scale
$215.81 Specs and fitmentA six axle road diesel with factory sound, and the SD40-2 is the single most common prototype in North America, so it is right for almost any modern era layout.
Best for: a first sound equipped road diesel
Check price on Amazon
Bachmann EMD GP40 DCC Sound Equipped Locomotive Union Pacific HO Scale
$227.82 Specs and fitmentA four axle road switcher, which is the more useful locomotive on a small layout because it takes sharper curves and looks right on local freight.
Best for: a small layout where a six axle diesel would look wrong
Check price on AmazonSide by side
| Model | Price | Scale | Proportion | Wheel arrangement | DCC | Onboard sound | Decoder type |
|---|---|---|---|---|---|---|---|
 Athearn HO SD40 Santa Fe Locomotive | $169.99 | HO | 1:87 | C-C | - | - | - |
| Walthers Mainline EMD GP9 Phase II with ESU Sound and DCC HO Scale | $184.99 | HO | 1:87 | B-B | Yes | Yes | ESU LokSound |
| Bachmann GP35 TCS DCC Sound Value Equipped Locomotive Great Northern HO Scale | $129.99 | HO | 1:87 | B-B | Yes | Yes | TCS Sound Value |
| Bachmann SD40-2 DCC Sound Locomotive Union Pacific HO Scale | $215.81 | HO | 1:87 | C-C | Yes | Yes | - |
How we chose
We did not test these products in person and we never claim to. Picks are researched from manufacturer specification sheets and instruction manuals, published NMRA standards and recommended practices, and the recurring themes in verified owner reviews. Every pick is matched to a real scale, a real minimum radius or a real current draw rather than to a price bracket, and it is placed in the tier where its capability actually belongs. Where a product is wrong for most layouts we say so on the page, and where a figure is a hobby rule of thumb rather than a published standard we say that too.
Sources
- Athearn published specifications for the SD40
- Amazon product listing features and current pricing
Frequently asked questions
How much does the Athearn SD40 cost?
It was listed at $169.99 when this page was last compiled. Model railroad pricing moves frequently and promotional pricing is common, so treat that as a planning figure and confirm the current price before committing to a purchase or budgeting a whole layout around it.
Is the Athearn SD40 right for my layout?
A DC layout, or a modeller who wants to choose the decoder. Beyond that, the honest test is whether its numbers match your space, your scale and your curves rather than whether it is a good product in the abstract. Work out what your layout needs first, then check this model against that answer.
Where do these specifications come from?
The manufacturer published figures, taken from the product listing and data sheet. We do not test products in person and we never claim to, so nothing here is a measured result. Where a specification is not published by the manufacturer it is omitted rather than estimated, which is why some sheets are shorter than others.
Will this work with my existing equipment?
Check scale and, for anything electrical, check the control system. A DCC decoder has to match the socket in the locomotive, a turnout has to match the rail code of the track it joins, and track has to match the gauge of everything else. Those three compatibility questions account for most returns in this hobby.
Is it worth buying this rather than the cheaper alternative?
Only if the thing it does better is something your layout actually needs. The alternatives listed above each trade something specific, and on a first layout the money almost always does more good spent on track and roadbed than on upgrading a single item of motive power beyond what the curves will show off.
Researched, not professional advice. This page is compiled from published manufacturer specifications, instruction manuals, published NMRA standards and recommended practices, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are hobby convention rather than a standard, and they are labelled that way wherever they appear. Always check a radius, a clearance or a grade against your own equipment before you cut wood or lay rail, because manufacturers vary and so does what your specific models will tolerate. Any permanent mains wiring in a layout room is work for a licensed electrician to your local code.