Since we don´t have an "amazing train footage" thread.....

[Benni]

...I am posting these fire-breathing monsters here, they get better (worse?) as the film rolls, or, as the cchinese OP wrote :
You will see very big spark in about 3 - 6 min.
https://www.youtube.com/watch?v=8grHpQAB1jA
some comments I found quite funny, too.

[Steve_D]

Looks like they are burning more coal than they are hauling.

Steve

[Yertis]

Wow. I'm just slightly to young to have seen them at work in the UK, but when they were would they have created such great showers of sparks, or is that entirely due to poor engine handling, coal type or what?

[silverfoxcc]

Possibly but not always

No spark arrester in smokebox

Full forward gear

Full throttle

You do get this on Srwam special nowadays, hence the ban when there is a very dry spell to minimise lineside fires.However that doesnt stop the odd one or two occuring when an electric decides to throw a few volts sideways!!

[Flying Phil]

Yertis said:

Wow. I'm just slightly to young to have seen them at work in the UK, but when they were would they have created such great showers of sparks, or is that entirely due to poor engine handling, coal type or what?

I think in steam BR days there would never have been such a display. It is most likely due to smaller bits of coal (pea size?) and a strong vacuum in the smoke box, caused by the blast pipe, due to hard working of the locomotive. It may also be that the Chinese locomotive has a mechanical stoking system? They tend to grind the coal into pieces.
I have recently seen on "You Tube" some fast runs of the TPO set at night on the GCR where there are a few sparks in the exhaust.

[matchmaker]

Flying Phil said:

Yertis said:

. It may also be that the Chinese locomotive has a mechanical stoking system? They tend to grind the coal into pieces.

That is the main reason, I expect. Mechanical stokers may make it easier for the fireman, but in terms of coal consumption they are horrendously inefficient when the loco is worked hard.