Industrial areas aren’t exactly known for their marvelous architecture or views. Rather desolate places they are, especially during weekends. Strolling around last Saturday yielded three interesting finds though, in less than 20 minutes. All heavily involved in the construction industry.
Starting with a 2019 Scania S500 4×2 tractor and a 2017 Pacton quad axle flatbed semi-trailer. A quintessential brick hauler, with its tall dropsides and diesel powered Kennis rolloader crane.
Besides bricks, such combinations are also used to carry (roof) tiles and all kinds of concrete end products. Over the past years, I’ve posted many of them, like here and here.
An advantage of a quad axle semi-trailer is that any 4×2 tractor will do to form a 50 tons/110,000 lbs combination, which is the national on-road weight limit. Furthermore, their weight distribution is perfect, especially when transporting partial loads. The Pacton’s third and fourth axle are steering axles (but you already knew that).
Note that the manufacturer rates their semi-trailer at a GVW of 54 tons/119,000 lbs (for the record, that’s without the weight of a tractor). An eight-wheeled brute, with plenty of overloading safety margin. Better show up with something really robust when you want to play in this league of trailers.
Over to an earth mover, a 2015 Volvo FH 6×2/4 tractor with a 2015 AJK end dump semi-trailer. The tridem axle set-up with super singles follows the usual Euro-recipe for semi-trailer chassis.
AJK is a Belgian company, specialized in manufacturing dump bodies for truck chassis and complete (semi-) trailers.
By the way, the location and the rig’s livery may look familiar.
Dump semis and others at work in this short impression of the Ploegam/De Klein fleet, as posted on YouTube. The company is big in hard infrastructure.
The last one of the short tour. Now I don’t know about other parts of the world, but semi-trailer based concrete mixers are highly common around here.
Their drum capacity ranges from 15 to 17 m³ (19.6 to 22.2 yd³). The design and shape of the frame rails indicate that the first and third axle of this semi-trailer are steering axles.
At the front of the chassis, the diesel engine to drive/rotate the big drum. Meanwhile, electric power units have arrived on the market.
The 2001 concrete mixer, built on a Lako chassis, teamed up with a 2008 Scania R480 6×2/4 tractor. A power combo, drum rolls only on working days though.
I have never seen a semi mixer truck, Seems like we have either conventional chassis with rear-outlet McNeilus mixer bodies or purpose-built low, offset cab straight trucks with front-outlet mixer drum. I sense that it’s a regional thing in the US.
It amazes me that one driving axle can provide enough traction on a working jobsite. I’m accustomed to two driving axles with the power divider locked being just adequate to move a straight truck, let alone a multi axle combination. Sometimes our dump trucks are equipped with differential locks which, if engaged along with locking the power divider, make all the drive wheels turn in unison regardless of traction conditions. Our ready mix trucks, mostly front-discharge rigs in our area of New England, are equipped at minimum with three axles, each with big single tires, all driving. Some have a non-driving, non-steerable tag axle. The driven front axle allows better steering control for the kind of close quarters maneuvering a mixer usually has to do. I don’t think the minimal ground clearance on the European rigs would be adequate for many of our jobsites, either. I wonder if our weather conditions (snow, mud, soggy ground, etc.) are the differentiating factor.
Usually, the first big rig that arrives at a working jobsite here brings and places road/trench plates. Used by anything that has to be there later on in the process.
Below a complete temporary road as an example, delivered by the semi in the background. The soil is normally way too soft (soggy) here for our heavy combination vehicles, an extra drive axle won’t help much.
GOM – Hardly ever see those FDM rigs on the West Coast, don’t know why. Maybe bridge formulas, maybe conditions. I think they use a lot of those in Florida.
Johannes – have you ever seen a front-discharge mixer like a Terex Advance in Europe, e.g. https://www.terex.com/advance/en/products/overview
I’ve seen them alright…but only in magazines and on the web, as front-discharge mixers are non-existent in Europe.
Across the continent: mostly an 8×4 cabover with a day cab. Common in NL: a 10×4 chassis (an aftermarket conversion of a factory 8×4 by a domestic specialist), like the Mercedes-Benz Arocs below. I wrote it up here:
https://www.curbsideclassic.com/blog/truck-show-outtake-2021-mercedes-benz-arocs-10×4-working-in-the-sonderklasse-of-concrete-mixer-trucks/
I have started to see see semi-trailer mixer truck rigs on the highway in California, according to what I have read those are McNeilus SMS sliding trailer setups. From 1/87-vehicles.org, article
Peterbilt 362 Day Cab & McNeilus SMS Concrete Mixer Trailer – By Kevin Shanahan
“These McNeilus SMS sliding Mixer units can legally haul 14 yards of ready mixed concrete in the state of California, grossing out at 80,000 lbs. These units feature a sliding rear tandem axle that extends to an overall length of 57′ which provides a distance of 39′ between the trailer kingpin and the center of the rear trailer axle. The 39 foot “bridge law” requirement in California allows the unit maximum legal GCW. Once the unit leaves the highway, the unit can be shortened up by approximately 7′, getting the overall length down under 50′.”
The norm is that the semi-trailer has its own power unit to drive the drum (like the one in the article).
There are exceptions though, the 22.2 yd³ drum below is driven by the DAF’s PTO. (photo courtesy of trailertotaal.nl)
Those are some serious trucks!!
Nice finds Johannes.
Looking at rescue convoys headed into Turkey and Syria today I see many of the tractors and rigs you have featured. Obviously they are not as shiny and clean as you have shown us because they are performing emergency duty and going as hard as they can.
In the western US the common thing on cement mixers and dump trucks is fold down rear axles to get more axle spread in bridge formula states. You also see flatbed trailers with widely spread axles and transfer box dump trailers instead of semi trailers. The transfer box is especially interesting because to dump, the truck is disconnected then driven on site to dump, then the driver returns ad winches the trailer dump body into the truck and dumps it, returns the body to the trailer, reconnects and goes for another load
A widely spread tridem axle set-up leads to 3,000 kg extra axle load/GVWR, that’s from 27,000 to 30,000 kg. A quad axle configuration is rated at 36,000 kg (4 x 9 tons axle load).
Good stuff, and mighty trucks. The semi trailer concrete cement mixer is not a UK regular by any means – too bulky for a regular construction site?
Too heavy for the UK, I guess. Note that it’s a shorty -overall length wise- with 6 axles in total and only 2 of them are non-steering axles (the tractor’s drive axle and the semi-trailer’s second axle). That thing can turn on a dime.