Single axle tractor with tri axel trailer

Is it legal to pull a tri axle 53' dry van with a single axle tractor unit? This would be for Canada.

My company has never tried this before so I'm just a little skeptical about doing it. I've definitely never seen anyone else do it.

Weight wise I'd be fine, about 19630 kg in the trailer. I'd likely need to slide the trailer axles but I'd still be legal.

 

Well we have 3 of them, we only have 1 tandem and it use to pull this tri axle trailer across Canada weekly but it's doing another trip right now.
We just don't haul enough weight to justify a tandem, well yet, they're getting tandem trailers now for us to use so we're ending up overweight sometimes with the single axle (the tandems don't slide on the trailer).

 

I was looking into it today and I can't do it, well I shouldn't say I can't do it but I shouldn't do it.
The truck is registered for 23,800 kg but the truck alone weights 9,778 kg, no idea what the trailer weighs but I'm already overweight with just the truck and product.

I mentioned it today so they're either going to go and increase the weight that the truck is registered for, or just wait until next week or this weekend and I'll use our tandem volvo 780

And yes, this truck is single drive axle. It's a peterbilt 382.