BBC Radio 5 live sports extra

BBC Radio 5 live sports extra are live with commentary of second practice - or you can listen by clicking the audio button at the top of this page.

Daniil Kvyat is trying to look enthusiastic...

Image source, Getty Images

Your F1-dog puns please - bonus points for pictures.

David Sullivan: I'll offer you Mika H-akita-nen & Cavalier King Charles Pic Spaniel #bbcf1

So, if Alonso gets a 35-place penalty, Ericsson takes his 10 places and Hamilton gets 75 places, we'll have passed the magic 100 mark for the weekend with relative ease. Huzzah!

On top of that, Sauber’s Marcus Ericsson will get a 10-place grid penalty because he needs a new power-unit. That makes it six turbochargers he has used this season.

Andrew Benson
Chief F1 writer at Spa-Francorchamps

Ashley Wilkinson asked on Twitter: "Will these new parts be expected to last the season, or will he potentially have to take another penalty?"

Mercedes are being quite coy about their plans for this weekend and the rest of the season, but it is almost certain that new parts fitted to Hamilton’s car for the first session were just the start of the changes this weekend - and the whole reason for that is to ensure he has enough parts to finish the season.

As Hamilton is over the limit on the turbo and MGU-H, any change to those parts incurs a huge grid penalty. So it makes sense to make as many changes as are theoretically needed for the rest of there season and get them out of the way in one go. So a second new turbo and MGU-H are expected to be fitted for the second session. And it may well be that he takes another new power unit as well for Saturday morning.

That is not completely clear, and it is complicated by the fact that there are rumours that a significant Mercedes engine upgrade is due for the Japanese Grand Prix in October. If Hamilton takes a new ICE here, in addition to the one he used in the first session, he would then be at five ICEs, which would mean he could not benefit from the upgrade in Japan.

Image source, Getty Images

Here's something for Lewis Hamilton to aim for.

Should he get up to a 75-place grid penalty, he will surpass Jenson Button's record of 70 at Mexico in November.

The even more farcical thing about Button's punishment was that he didn't take part in qualifying because of a mechanical issue and would have started at the back of the grid regardless.

It was all pointless and brilliant.

Image source, Getty Images

So, Lewis Hamilton will definitely suffer a 15-place grid penalty for Sunday's race. But, in reality, that could grow to a record 75-place grid penalty

How, why, what, huh?

All very good questions. Here are some answers:

• The world champion has a 15-place grid penalty for using too many engine parts. Hamilton took a sixth turbo and MGU-H for today - one more than the number of parts each driver is allowed to use in a season
• More changes are expected to parts on the engine, potentially taking the penalty up to 75 grid places
• Why change everything on the same weekend? Well, there are only 22 cars on the grid, so you might as well take the hit all at once and start 22nd. They can't make him start 75th
• Isn't this a bit odd? Yes. But it's F1 - don't pretend you're surprised.

BBC Radio 5 live sports extra

Second practice gets under way at 13:00 BST.

Listen online - by using the button at the top of this page - or by tuning into BBC Radio 5 live sports extra from 12:55 BST.

Image source, Getty Images

We've never professed to be high-brow here on the F1 desk.

And that's why we're snaffling the opportunity, on national dog day, to get your F1-dog puns.

Here's a few to get you started:

Jean A-leash-i

Giancarlo Fisi-terrier

Niki Lead-a

And my personal favourite - Rene Arnoux-foundland.

Yup. It's national dog day.

So here are some adorable creatures.

With some dogs.

Woof!

Image source, Getty Images

Nico Rosberg set the fastest time of first practice, and did it beneath the glow of the proposed safety device known as the halo.

And he may have someone looking over him, with Mercedes team-mate Lewis Hamilton taking at least a 15-place grid penalty this weekend.

Welcome back for second practice at Spa.

That's it from first practice. It's a slow burner, hopefully building to boiling point on Sunday.

Get the full low down on that session through the expert eye of Andrew Benson here.

I'll be back at 12:30 BST, with commentary online and BBC Radio 5 live sports extra at 12:55 BST.

You'll join us, won't you?

Red Bull boss Christian Horner on Lewis Hamilton taking a set of penalties all on the same weekend.

"It's what the rules are. We did the sane in Australia last ear. You can't go further back than the back of he grid," he tells Sky Sports.

Other times of note.

Jenson Button, in an upgraded McLaren, in P18 and four seconds off Rosberg.

Esteban Ocon, on his first full race weekend, out-paced Manor team-mate Pascal Wehrlein by just over a second.

And Fernando Alonso had a miserable session, retiring after a water leak. More on whether that will require engine changes when we get it.

So, it wasn't exactly an explosive return to action for F1.

But hey, it's called practice for a reason.

Here's your top five:

Nico Rosberg sets the fastest time - 1:48.348

Lewis Hamilton +0.730secs

Kimi Raikkonen +0.799secs

Sergio Perez +0.926secs

Sebastian Vettel +1.420secs

Image source, Getty Images

Dutchman Max Verstappen is very well supported over the border from his home country here.

Plenty of orange on show - and he's lapping it up on a meandering saunter around Spa at the end of first practice.

Plenty of fans loving it, including one woman who almost falls down an embankment.

A frustrated looking Fernando Alonso is sneering at computer screens while someone points at stuff. It doesn't seem to be helping that he's out of this session without setting a time.