First I must answer to your question “What trucks?” by writing little introduce to this Finnish truck manufacturer founded at 1931. They have used various engines and gearboxes over the years and one of the engine makes being longest available has been ■■■■■■■■ Now they dont offer ■■■■■■■ anymore as there isn’t any convenient Euro 4 models available. During last year they have practically renewed their whole engine range which now consist 13 liter Renault DXi (Volvo) and 13 and 15 liter Caterpillar engines. They’ve also used Renault Premium based cab from -97, but that’s where common parts stop. Sisu’s homepage is found from http://www.sisuauto.com/.
Now to the pictures, and I must apologize from dial-up users as I’m going to post quite many pics.
Beginning from the oldest, Sisu model M from 70’s, equipped with Rolls-Royce engine and Fuller gearbox. It has been rebuilt to “low loader”, so no need to do “Thai style excavator delivery” 
This rigid is probably being used to carry forestry machines.
Another “oldie”, Sisu SR270, which came into production at 1982 and was in production until Renault cabs replaced genuine Sisu cab. This is quite basic 8x2 tipper which are still quite usual sight despite even newest of them are at least 10 years old. I don’t know which engine this truck has (my wild guess would be ■■■■■■■■■ but it has 270 kW which most likely means it’s equipped for pulling a trailer.
Yet another oldie, Sisu SL210, with “low” version of hooded daycab opposed to the “high” version in picture above this. This truck has, like model number says, 210 kW engine (and Fuller gearbox 
) probably meaning it’s never pulled a trailer. Behind is another Sisu 6x2 tipper, but much newer with Premium cab. Notice snow plough readiness in both trucks. Bottom blades at least are easily noticeable, and bumbers are modified for front plough to be equipped. There are also plough lights which are used with front plough.
Sisu SM372 cabover which design also derives from 80’s. This 8x4 tipper is equipped with it’s time top of the range 14 liter ■■■■■■■ with 372 kW (500hp) giving good ride for 60 tonnes in hilly terrain typical to the middle parts of Finland. Gearbox is, of course, unsynchronized Fuller. I don’t know if this type of non-tipping trailer is familiar over there, but basic principle is that after pulling rigid has tipped it’s load it takes body from trailer and tip also it’s load.
Low version of Sisu cabover, Sisu SK250, which seems to be equipped with wirelift and has snowplough readiness.
Sisu E14 8x2 tipper from -96 or -97 with facelifted sleeper cab. This truck also has 14 liter ■■■■■■■■ but only with 425 horses giving it enough pulling power to cope with trailer in much more flat parts of Finland.
And yet another tipper. It looks like Sisu is liked among tipper operators (or disliked among other operators ). This truck is operated by state-owned firm in at roughly same area as blue SM with orange stripes couple pictures earlier. Despite hilly terrain truck is equipped with only 425 version of 14 liter ■■■■■■■■ My summer job (white Volvo) also managed to get into picture.
Very unusual to see artic logger here in Finland. Another as unusual thing is to see someone tramping in a logger. This logger is used to haul long logs (or wooden pillars in this case) all around Finland which explains also tramping in a logger. Trailer most likely is extensible and has steering bogie to help getting out of the forest. This Sisu is equipped with 12 liter Mack with 440 horses.
Sisu bulker hauling cement all around southern Finland. Running at full 60 tonne weight and having only 11 liter ■■■■■■■ with 405 horses makes sure fuel figures aren’t anything to be proud of 
Trailer with small tyres is also there to make figures even worse…
Couple typical loggers spotted on a break. Hindmost is equipped with 18 liter Caterpillar with 630 hp way before Volvo introduced “worlds first mass-produced truck with over 600 horses” 
Engine is most likely coupled to a 18 speed Fuller gearbox, but this engine has also been available with ZF synchro box.
Not as rare sight as artic logger, but rare sight nevertheless to see Sisu with cargo box. I chatted with driver of this truck and he mentioned that he had had full load of mattresses which weren’t any match for his ■■■■■■■■ but had taken juice out of him as he handballed those during the day
Yet another tipper, obviously washed yesterday, but what makes this picture special is that this truck is 8x4 but only two axles are touching ground 
Something what isn’t yet invented in country where almost every truck has double drive Sisu is famous here from it’s detachable double drive and from tag axle which will raise off the ground even with full load.
Typical sight to see smaller earth moving and construction equipments being moved on a flat trailer being pulled by a tipper.
10x4 tipper equipped with 480 hp Mack engine giving nice ride for 38 tonnes.
Old artic used by smallish steel works company to haul their own products. Note lift axle with plenty of space between it and the ground In Finland this axle configuration allows 44 t GVW.
Sisu with 480 hp Mack hauling animal feed. Truck is running empty as 2nd and 4th axles are lifted.
When you Harry think they might have been using it?