One of the very first high-volume dirt haulers, bottom dumps were very popular for bulk haulage and are still in use today. By Richard Campbell
Not a machine type often seen in New Zealand, but a very important piece of equipment overseas, bottom dumpers made a name for themselves on large dam projects all over the world.
The very first bottom dumpers were locally made affairs, usually constructed from wood with strap steel reinforcing and drawn by a horse or oxen team.
Their capacity varied depending on who manufactured the bottom dump, but it was usually around 2 cubic yards.
Loading was initially by manual labour – teams of men with shovels, but in the late 1800s, the first small steam shovels began to appear and these replaced the back breaking task of filling the bottom dump literally by hand.
Once loaded, the horses or oxen would trot off to where the load was to be deposited and someone would pull the trip cable releasing the dump doors and that was that.
The principle has not changed and is still the same today.
However, more modern bottom dumpers can spread ‘on the go’ rather than depositing a heap of earth which would require later spreading.
It should be mentioned at this point that bottom dumpers have their limitations, and while excellent receptacles for the carriage and spreading of large amounts of earth, coal, sand, gravel, grain and most ores, bottom dumps do not like rock at all!
With the large-scale expansion of earthmoving jobs following WW2, there was also a proliferation of manufacturers offering their own take of the bottom dumper concept.
Many of these manufacturers did not last too long in the industry, while others flourished.
We will examine some of the more notable manufacturers across the decades in a little more detail.
Euclid Road Machinery Co., was a very early exponent of the bottom dumper and remained so right up until the disastrous IBH buy up from General Motors in 1981.
Euclid’s first bottom dumper was introduced in 1933, a 3-axle machine which carried 10 cubic yards and was powered by a Waukesha gasoline engine.
By 1940 diesel engined examples had replaced gasoline powered machines entirely in the Euclid range.
All of Euclid’s 2-axle prime movers could be ordered with a bottom dumper including the massive model SS-40, later known as the B-63, and the B-100 which was the largest bottom dump hauler that Euclid ever built on a production line basis.
Euclid fabricated all its own bottom dumpers that were famous for their toughness.
One of the preferred suppliers when contractors went shopping for this type of gear, Euclid finally discontinued the manufacture of bottom dumps in the early 1970s although its ‘33-series’ off highway trucks (by now renamed Terex), were available as tractor units to provide the pulling power for other manufacturers bottom dumpers, notably Athey, right up until the late 1990s.
International-Harvester bought the earthmoving division of Heil in December 1953 and in so doing, acquired a bottom dumper which was re-branded as an International-Harvester product.
This was usually installed as trailing equipment on the 2T-75 motor scraper tractor with the unit being redesignated 2W-75, the W standing for wagon.
Very few of these units were manufactured and as far as the author is aware, none exist today even in preservation.
International had considerably more success with its larger 495 scraper tractor which was mated up with a bottom dumper of their own design, which held 40 cubic yards.
Quite a few of these machines were manufactured and used in dam construction in the continental USA and in Asia.
As with the 2T-75W, it is very unlikely that any survived.
International retired from the bottom dump business in the late 1960s.
LeTourneau offered bottom dump trailers for its model A, B and C Tournapulls right up into the mid-1960s.
Due to the hitch neck design of LeTourneau tractor units, trailing attachments could be easily swapped out for other trailed units by disconnecting the plug on the electrical wiring loom and undoing four large bolts.
Early bottom dumper designs had quite a steep inside wall profile which tended to make the material being carried block the discharge doors, especially if the material being transported was damp. A design change in 1955 altered the interior profile to a more rounded ‘fat belly’ type and that solved the problem.
The bottom dumper option had been discontinued from the LeTourneau range by the time LeTourneau-Westinghouse machines had made the transition to the Wabco name in the mid-1960s.
Like International-Harvester, Allis-Chalmers acquired its bottom dumper from another manufacturer, in Allis-Chalmers’ case this was LaPlant-Choate, a company Allis-Chalmers bought outright in September 1952 in order to get its hands on LaPlant-Choate’s motor scraper range.
LaPlant-Choate had only one bottom dumper, its model TW-300 which held 19 cubic yards and was powered by a Buda 6DAS844 diesel engine.
When Allis-Chalmers took over it simply repainted the existing LaPlant-Choate stock from Hi-way Yellow to Persian Orange and it was business as usual.
An optional Cummins NHS600 was offered for a time but Allis-Chalmers had effectively exited the bottom dump business by 1956.
Caterpillar and Athey.
Caterpillar entered the bottom dumper business with its model DW-10 tractor unit combined with a W10 bottom dump in 1941.
World War 2 temporarily put a stop to production but once the dust from that conflict had settled Caterpillar were right back in production again.
The DW10 was discontinued in 1954 and its replacement, the DW15 also utilized the W10 bottom dumper.
In 1951 Caterpillar introduced the larger DW20 which could be mated to a model W20 bottom dump.
Both bottom dumps were built entirely by Caterpillar, the W10 holding 14 cubic yards and the W20 25 cubic yards.
Around 1960, Caterpillar entered into an agreement with the Athey Products Corporation to manufacture trailed attachments for its new 600-series tractor units that were then coming onto the market.
Athey were a specialist company that built a wide range of trailer attachments suited to single and two axle motor scraper tractor units including rock haulers, side dumps and of course bottom dumpers.
This saved Caterpillar vast amounts of R&D costs and also freed up manufacturing space at both the Joliet and Decatur manufacturing facilities where the new 600 series machines were built.
As far as your author is aware, this agreement is still in place today although the demand for equipment such as bottom dumpers has tapered off considerably.
For the model collector.
Model collectors are reasonably well catered for when it comes to models of bottom dumpers.
The majority of these models are limited run, to 1:50 scale and generally available from the better model dealers in the USA (Buffalo Road Imports and DHS Diecast).
They include the Euclid SS-18 (14TDT), Euclid B-100, Caterpillar DW10, Caterpillar DW20 and Caterpillar 660 (with an Athey bottom dump), plus the rare Heil 2C200 and International 2W-75.
There are also several resin kits of more exotic subjects that you can build yourself