REVIEW / ACTION-COMEDY

RAILROAD TIGERS (PG)

125 minutes/Opens tomorrow/2.5/5 stars

The story: Ma Yuan (Jackie Chan) is the head of a group of railroad workers who regularly steals supplies from the Japanese military in east China in 1941. Tipped off by a Chinese soldier (Darren Wang), they get a shot at accomplishing something big - blow up a bridge to disrupt a key enemy supply route. Ma's crew also includes noodle-seller/ sharpshooter Fan Chuan (Wang Kai) and tailor Dahai (former Exo member Huang Zitao).

Action star Jackie Chan and his son Jaycee provide some of the more amusing moments in this middling film.

Although Jaycee is missing from promotional material and even from online write-ups, he plays a member of Ma's crew. Some have speculated that this is Chan's way of giving his son a leg-up after the latter's show-business freeze because of his marijuana-related jail stint.

Whatever the reason, father and son are pretty entertaining to watch.

In one scene, after being captured, they happily trade insults over each other's looks instead of being worried - Jaycee even scores a big hit with a jibe at his father's bulbous nose.

And during an attempt to steal explosives from a Japanese warehouse, they end up on two ends of a rope thrown over a metal beam - like two ends of a human pulley system - yo-yoing up and down as soldiers prowl the premises.

The key hook of the film - which reunites Chan with Ding Sheng, his director for crime thriller Police Story 2013 and period action flick Little Big Soldier (2010) - is how a motley crew with few resources go about destroying a bridge.

It has promise, but Ding takes too long to kick things into gear, burdened as it is with too much unnecessary cargo, from the superfluous framing device to the sprawling cast of characters.

Xu Fan is wasted in the role of a hawker who is sweet on Ma and Zhang Yishang barely registers as Ma's daughter. At least Wang Kai (Nirvana In Fire, 2015) leaves an impression as the cool sharpshooter Fan.

The finale, which is predictable, needs better computer-generated imagery for the flick to end with a roar.