Classic Machines Scrapers

Classic Machines: The Terex TS-18 motor scraper

Breaking away from traditional Terex design philosophy, the TS-18 twin powered motor scraper was an entirely new machine from the ground up. The only link with the past was the name “TS-18” which had been used on a previous Euclid branded machine that had been discontinued in the mid-1950s. By Richard Campbell.

Terex engineers had pretty much started with a blank sheet of paper when they designed the TS-18 and, using test data from the field, comparisons with existing machines plus suggestions from contractors, came up with what they hoped would be a fast, high production earthmover.

Fitting in between their existing twin powered scrapers, the TS-14 and larger TS-24, the TS-18 had a struck rating of 18 cubic yards with a heaped capacity of 24 cubic yards.

Introduced in 1970 after considerable testing, the TS-18 quickly established a niche for itself amongst contractors’ dirt moving spreads. As with all new things, sometimes testing doesn’t always iron out all the bugs and the TS-18 was no exception.

Problems came to light with tyre rim cracking and more disturbingly, rear engine oil starvation issues resulting in failures. Terex soon had fixes for both of these problems however – heavier, thicker tyre rims and a redesigned, deeper rear oil sump and pickup bell – and it was back to business as usual.

One of the most radical features of the new TS-18 was its power down bowl.

All previous Terex (and Euclid) scrapers had relied on single acting hydraulic cylinders, linkages and gravity for bowl drop and cutting edge penetration but the TS-18 featured two double acting hydraulic cylinders acting directly on the scraper’s spreader bar and could exert a downward pressure of some 28 tons, more than enough to cut through tight packed clay which had sometimes proved problematic for earlier machines.

The new setup also allowed ‘pump loading’ of free flowing material such as sand, a task which was often difficult on earlier Euclid and Terex machines.

An option which a lot of users fitted to their machines was Terex’s “Twin-Hitch” system, an attachment that allowed two TS-18s to load each other in tandem, the same manner as Caterpillar’s “Push-Pull” and International Harvester’s “Pay-Mate”.

Unlike Caterpillar and International Harvester, whose tandem loading units were factory fit only, the Twin-Hitch could be field installed to existing machines with minimal modification.

An Athey rock dumper rated at 30 tons capacity could also be installed according to user requirements.

Another development of the basic machine was the S-23E elevating scraper with a bowl assembly developed by Hancock. However, this machine falls outside the scope of this feature and will be covered in a future article.

Terex upgraded the TS-18 to the TS-18B in 1978 with more horsepower in the tractor unit and a transmission change, however the type was, sadly, discontinued in 1982 when Terex ceased manufacturing of most scrapers in the USA. European demand for the type did not apparently warrant shifting the jigs and tooling to the UK for manufacture by Terex in Scotland.

The TS-18 described

As befitting a Terex product, the TS-18 had an all GM powertrain consisting of an 8V-71 naturally aspirated V8 diesel in the tractor unit and a 6V-71 naturally aspirated V6 diesel in the scraper with matching Allison CLT4465 powershift transmissions.

A fast machine, the TS-18 could zip along at 33mph, fully loaded.

Brakes were full air operated S-cam shoes on all wheels.

Usual tyre equipment was 29.5×29, 34 ply E3 but there were quite a few other options that could be installed at the buyers request.

Steering differed from previous Terex machines as the gooseneck assembly was unlike any previous model. Instead of the usual follow up system, which had been is use since 1954, a more direct method was applied, similar to that used by Wabco on their hydraulically steered scrapers.

As mentioned previously, the bowl held 18 cubic yards struck and 24 cubic yards heaped, and was fitted with a standard Terex layout four-piece reversible cutting edge.

The apron was power up and down using double acting hydraulic cylinders on either side of the bowl. Apron arms were mounted outside of the bowl and did not have to force their way through loaded material in order to close.

The rear engine sat a bit higher than on previous Terex scrapers and was covered by a tapered bonnet that sloped to the rear giving the machine a slightly humpback profile.

TS-18s were one of the first Terex scrapers to feature the ‘keystone’ styled radiator surrounds, which would eventually become standard throughout the entire Terex scraper range.

Along with the Keystone styling, the operator’s compartment of the TS-18 was the first in the scraper range to feature the new imitation wood-grain dash panel and revised instrument layout.

Terex scrapers were always well instrumented and the TS-18 was no exception. Levers were set to the operator’s right in a panel and the bowl lift lever incorporated a switch which could be activated to drop the apron when the bowl was raised.

Seat options included the standard Milsco air suspension model or the luxury Bostrum suspension seat, which compensated for the operator’s weight.

Visibility was very good indeed except to the right hand side, which was partially obscured by the air cleaner stack.

Although a ROPS canopy was not a standard fitment when the machine came out, the mounting pads for it were. An insulated cab was also available as an optional extra and included a heater.

The New Zealand connection

New Zealand contractors embraced the TS-18 with open arms when it was first introduced. Clyde Engineering, the Terex franchise holder at the time, imported sixteen TS-18s, all of them 33TOT-92SH series. There may also have been a couple of private imports but as far as the author is aware, no TS-18Bs came into the country.

The first customer to receive a TS-18 was Herron Contracting in the South Island who bought a pair. Subsequent users have included Taylor & Culley, Feast Contractors, Downer Construction (who had five at one stage), Daryl McGregor, Picton Developments, V.A. Draper and C.A. Levein.

TS-18s saw widespread use at the Twizel hydroelectric scheme in the mid 1970s where they were highly regarded.

And you can still find TS-18s in use today.

For the diecast model collector

Regrettably there are no models available in any scale of the Terex TS-18.

Due to cloudy licensing issues surrounding some of the Euclid/Terex product line it is probably unlikely that one will ever be issued unless one of the boutique manufacturers such as EMD, Dan Models or Black Rat take up the challenge.

Brief Specifications – Terex TS-18

Engine (front): General Motors 8V-71N, 2-cycle, naturally aspirated V8 diesel rated at 292 flywheel horsepower at 2100 rpm

Engine (rear): General Motors 6V-71N, 2-cycle, naturally aspirated V6 diesel rated at 225 flywheel horsepower at 2100 rpm

Transmissions: 2 x Allison CLT-4465 6-speed full powershift

Top Speed: 33 mph

Brakes: Air operated expanding shoe type on all wheels

Steering: Full hydraulic, 90° each way

Turning Circle: 37’ 8”

Std.Tyres: 29.5×29, 34-ply E3 type (with many options available)

Capacity: 18 cubic yards struck, 24 cubic yards heaped

Operation: Full hydraulic

Length: 41’ 11” (with standard pushblock)

Width: 11’ 10”

Height: 12’ 4”

Operating Weight: 33 tons (empty), 63 tons (loaded)

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