These charming old MLW's were a common sight before SLR had a lot of leased power, eager to demonstrate their burbling engine sounds and remarkable ability to smoke when accelerating.  Although they may sound odd, they were ground-shakers, able to match or surpass pulling ability of competing EMD GP-series diesels of the same era and horsepower.   Most recordings are from near Waterville, QC.  All the M420W's were sold prior to 2003.

All recordings are 22050 Hz unless otherwise noted.

Recorded July 2000, 36 seconds
11,025 Hz compressed, 142 KB

Many people consider the M630/M636 to be the big brute of freight haulers--indeed, it could outpull even the ultra-popular and reliable SD40 series from EMD.  The M420W is essentially a scaled down version of that powerful but trouble-prone locomotive, minus most of the reliability problems.  Both were known for there smoke, pulling ability and burbles, and are an impressive sight when leading a heavy train in multiple.  Case in point: These four M420W's, whose putt-putt was audible when they were nearly two kilometers away. 3505's horn helps add to the overall impression, with its vibrating chimes creating a gruff sound.

Recorded August 2000, 43 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 293 KB
44,100 Hz, 1,847 KB

Going along at over 30 mph, two M420W's and GP40's 3000 (with its rpm restriction) and 3717 roar past with SLR freight 394.  The speed can be judged by the noticeable drop in pitch of the engine whine of 3717 (caused by the Doppler effect).  The pleasing K3H of 3512 is a major chord instead of a minor, hence the happy rather than haunting sound.

Recorded August 2000, 57 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 387 KB
44,100 Hz, 2,446 KB

Three M420W's, led by 3512, and one of the GATX GP40's (either 3702 or 3717) are in charge of this 394 freight headed towards Waterville, QC, on a summer afternoon.  The roar and whine from the single Geep can be heard over the MLW's after they pass.

SLQ M420W 3512 leads locomotive after locomotive after locomotive on this train-- five more, to be precise.  After the lead M420W came two more M420W's (all burbling) a GATX GP40, SLR GP40 3000, and another GATX GP40.  Here, a somewhat ignorant driver (to be polite) eased onto the tracks just before the third whistle (where a "vroom" can be heard), stopped, watched the train come, then accelerated off the crossing with less than five seconds to spare.   Not wise in front of a 15000-horsepower freight weighing over 10000 tons!  Note the turbochargers whistling on the Geeps--  3000 has a lower whistle than the others, caused by its restricted engine rpm (which ended in October 2000).

Recorded September 2000, 38 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 258 KB
44,100 Hz, 1,628 KB

Among the four locomotives on this train, one can be heard over all the rest: SLR GP11 8749.  It was following M420W 3512 and SLR GP40 3733 and ahead of SLR GP40 3000, and makes a lot of noise despite being the least powerful locomotive in the consist.  Credit the four exhaust stacks for providing a free exhaust flow and resonating the sound.  A low-pitched droning came from SLR GP40 3000, which still was not running at full engine speed.

Recorded June 23, 2000, 46 seconds
11,025 Hz compressed, 181 KB

SLQ M420W 3517 leads another M420W and a GP40, in run 5 or 6.  The horn on 3517 was probably the best of the old M420W's.

Recorded May 2001, 32 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 216 KB
44,100 Hz, 1,364 KB

Recorded during the time before train 394 became the sole (huge) Eastbound scheduled freight, SLQ M420Ws 3517 and 3579 ease a short Intermodal freight South early in May 2001.  The engineer yelled a greeting out the window, but was indecipherable over the gruff grumbling of the MLWs racing past.

Recorded August 2000, 35 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 238 KB
44,100 Hz, 1,502 KB

Here are two M420Ws hauling a mixed freight uphill, with the typical MLW engine sounds.  The last whistle of 3519 is quite long, resulting in a pleasing Doppler effect.

Recorded October 2000, 1 minute 2 seconds
Re-transferred October 29, 2006
22,050 Hz compressed, 421 KB
44,100 Hz, 2,662 KB

M420W 3562 is at the head of this train being hauled downhill (West) from Waterville, QC, by a mix of M420W's (burbling) and GP40's (droning and whistling).  The Nathan K3RH2 horn on 3562 is gruff and out-of-tune, albeit with all three chimes still functioning.

What happens when a train travels when it's snowing and the temperature is just hovering around 0 degrees Celsius?  Listen to the horn on 3562 to find out!  The #2 chime (between the low #1 and high #3) is the only one sounding--probably because it's facing backwards and is therefore immune to snow accumulating.   Following were CN M420W 3578 and SLR M420W #3517, and the three of them burbled past in mid-throttle with an eastbound freight.

Recorded October 2000, 1 minute 14 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 504 KB
44,100 Hz, 3,181 KB

Though not exactly in tune, the horn on 3569 was better than those on most of the other M420Ws.  Here, the unit is in front of various other MLW and EMD units (among them an unmistakably chugging GP11) on train 394 going by after dark.  I'm not sure what pattern the engineer was following as to the sequence of horn blasts, but the result is interesting.

Recorded September 2000, 35 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 243 KB
44,100 Hz, 1,532 KB

I don't have any recording of any locomotive type anywhere that has more burbling engine sounds than this!  M420W's 3573 and 3579 lead a short eastbound train towards Waterville, QC, on a sunny afternoon.  3573 was known to make substantially more smoke than the other MLW's, but whether this was related to the engine sounds, I don't know.

Recorded May 2000, 19 seconds (Engines passing)
11,025 Hz compressed, 76 KB

1 minute 58 seconds (Entire train)
11,025 Hz compressed, 461 KB

This was my very first recording of an SLR train, with two M420Ws and a GP40 leading 57 cars on Train 394 headed uphill towards Waterville, QC.  The MLW's have their typical burble, but don't expect any low rumble from any of the engines--this is one of the few early speaker-to-microphone recordings that's no longer on tape.  Standing down a ways from the crossing, as well as having the engineer blow the horn in a nearly ideal sequence, created a very pleasing Doppler effect.

A recording of 3578 and another CN-painted M420W, passing East in run 7 with 17 cars and typical burbling engines.  I didn't mark down locomotive numbers at the time, but chances are the second M420W was the same as in the recording above.

Recorded March 2001, 55 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 375 KB
44,100 Hz, 2,370 KB

SLR crews have such senses of humor!  In the cab of 3578, the conductor waved and yelled "whoo-hoo!" out the window (which turned out in the recording) and threw out a roll of toilet paper!  I'll have to add it to my collection of railway-related artifacts!  Behind 3578 was yellow-painted M420W 3517, and the two locomotives eased along an 18-car freight.  The bell on 3578 sounds quite loud, due to the (relatively) quiet engines and the bell's placement on top of the cab.

I've been very selective about which recordings of 3579 I upload, simply because I have nearly a dozen of them; this is one of my favourite ones.  Behind 3579 is another ex-CN M420W and the two GATX GP40's (3702 and 3717, which are now SLR 3001 and 3002).  The M420W's pass in an airy chorus of turbocharger whistles and traction motor whines, while the GP40's roar past afterwards with whining radiator fans and more turbo whistling.

Recorded September 2000, 59 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 401 KB
44,100 Hz, 2,529 KB

This train was recorded from an interesting vantage point, to say the least!  I was in a ditch beside an embankment, at about the level of the rail, on the inside of a curve, with the train towering (and leaning inwards) over 15 feet above me.  On top of that, it was pulled by six M420Ws raging along at over 30 mph (50 km/h)--which is about as fast as the trains get on the SLR.  I didn't stay there for the passing of the whole train--it was a little unnerving!

As in the recording above, centerbeam flatcars at the front of the train, which have an overall length the same as two rail-lengths, produced a peculiar rhythmic clicking sound.  Another tic-tic-tic-tic-tic came from a car with a tiny chip in one of the wheels.

Another recording of 3579.  The vintage-1976 MLW was here leading three other airy-sounding MLW's in run 8 on a late-running 394 freight.  This was recorded some distance from the tracks.

Recorded September 13, 2001, 52 seconds
Re-transferred September 27, 2006
22,050 Hz compressed, 357 KB
44,100 Hz, 2,251 KB

By August 2001, trains 393 and 394 had been combined with the smaller Intermodal freights, and four to six Geeps (and the occasional M420W) had them under control.  But SLR also ran (and runs) local trains in Eastern Townships region, often with an Eastbound passing through Waterville, QC in the afternoon and returning West an hour later.  This eastbound train of perhaps 18 cars was led by M420W 3579 and GP11 8749 in throttle 5.  Knowing that the train would make a return trip, I stayed and waited for it-- the recording is in the SLR GP11 Section.  The whole train was recorded.

At the time of this recording, 3579 was the last remaining M420W in service, and both it and the GP11 were on borrowed time.