Was this MLW/Alco answer to the EMD G12? This RSD8 demonstrated on both the CPR and CNR with differing road numbers.
Rather odd looking thing. Lotta truck, C-C, small car body, styling pretty spartan.
No orders ensued domestically. Just as well.
MLW 7008 demonstrating with CP dynamometer car 62 at Trois-Rivieres, QC. April 2, 1958 Rober Boisvert/Digital restoration Walter Pfefferle
RSD8 DL531 C-C 900 HP Alco 82837 2/1958
Note: Built as first of 10 unit export order to Paulista Railway in Brazil.
It was redirected to Canada and first demonstrated 3/1958 as 1735 on CNR.
(CNR’s RSC13’s were numbered 1700-1734)
Then 4/1958 on CPR as 7008 demonstrator series (7001-7009).
No orders came forth. 5/1958 became 909 Paulista Ry.
“Strange” is appropriate here because they’re export units, designed to suit alien conditions. I’m surprised no one has invoked the earlier Alco MRS-1.
Even stranger looking, perhaps (to our eyes), are the BR class 59 (an English SD40) and following class 66.
Building for alien conditions can give an alien appearance. (Some builders had relatively less issue with this; the Baldwins that replaced the Algerian Garratts are clearly recognizable as contemporary Baldwins.)
213 were built locally and more than thirty are still in service today.
They were also used in Pakistan, but India went for the DL535.
There was a four axle version, the DL532 which was the standard locomotive in Jamaica and a batch went to Korea.
As Colin indicated, the DL535 used the 251D which had an air to air intercooler and the notch 8 speed raised to 1200 rpm and was popular in Argentina where it was used to replace older Cooper Bessemer and FIAT engines as well as in a large fleet of DL535s on the broad gauge.
But the type was at least as successful as most Alco types and directly led to the DL 535 which was one of the most successful diesel locomotives of all time, based on production in India.
India is Alco heaven. DL560’s in several variants (WDM-2 and others) are in service all over the broad-gauge network and DL535’s (YDM-4) are the prime power on the slowly shrinking meter-gauge network.
It was in Australia. The ones that are left tend to be used in yard and local service, so getting them out on the main was a treat. The string of them included three DL531s and a DL500G, which as the last one in revenue service was just as good as the DL531s.
Much of the unusual proportionality compared to the road switchers we’re used to comes from a combination of the long trucks (to spread weight), short length (due to the 6-251) and short height (for clearances). 12-cylinder DL541s are much closer, being taller and longer.
The Alco MRS-1 was effectively a low clearance RSD-4 with special trucks.
The export version was the DL541 and DL543, basically a cut down RSD-12 by that time. The DL541 is 1800HP, the DL543 2000HP. Both had optional trimount or World (DL500) trucks. Apart from Australia, where 47 DL541s were built (with Trimounts) there were DL541s in Chile and DL543s in Pakistan.
The DL531 is noticeably smaller in all dimensions than the DL541.
Even the trimount trucks are a special lightweight version, 12’0" rather than 12’6" wheelbase.
But the appearance of the DL541 was very like the Alco MRS-1.
EMD planned to offer their MRS-1 as an export model R.
In fact, they modified the model G12 as the GR12, a big hit in South America.
I have an EMD advertisement from I think 1956 showing the R, B, G8 and G12.
The R generally resembles the G16 which supplanted it in the EMD catalogue around 1958, with similar trucks and body, with one notable exception: the model has a radiator arrangement similar to the domestic SD7, with four small radiator fans on the roof and a screened intake just below that. This might’ve been to deal with the troublesome right-angle fan drive coupling in the G8/G12 radiator, but the later G16 had the standard G series radiator.
I’m guessing the whole G family came from the MRS1 development, as it was introduced shortly after.
What exactly distinguishes a GR12 from a G12? I’ve never been able to find a satisfactory explanation.
The first evidence of the model G I have seen is a letter from EMD to its associates regarding what became the G-8 and G-12 dated 28 June 1951 indicating the general characteristics of the proposed locomotive. This is a year before the appearance of the MRS-1, so the two designs may have been developed in parallel.
Other correspondence I have seen relates to Clyde complaining that they had nothing to offer that would compete with General Electric’s tender to the Queensland Railways that resulted in the 1150 class. This had a twelve cylinder Cooper-Bessemer rated at about 1200HP and six traction motors. The GEs arrived in 1952 but Clyde built a G-12 demonstrator for Queensland in 1955, which was purchased along with twelve others. They later had the majority of or
I’ve seen other less-than-reputable sources detail a heavier, stronger frame for the GR12, but that would’ve meant extra weight, certainly not suitable for many areas.
