The main characters seem tailor-made for McLaglen and Lowe's long-established battling-bros screen personae, dating back to the blockbuster war comedy What Price Glory (1926), a lip-readers delight that spawned a series of Pre-Code sequels that saw the stars wreak havoc around the world. Here as there, the stars play ball-busting he-men for whom friendship is indistinguishable from angry rivalry for accolades or ladies' attention. Their sandhogs are working from one end of the East River as another team, led by an even greater asshole (Charles Bickford), vies for the prestige of meeting in the middle first. There's not much plot beyond that. If anything, the screenplay is more episodic than the pulp serial, a 72 minute feature necessarily being but a digest of the novel.
Above, Edmund Lowe kayoes a dues-paying Ward Bond.
That makes him credible when Victor McLaglen threatens to throw down with him (below).
The sandhogs -- a racially integrated workforce, though the blacks (in Argosy, Chase identifies them as Senegalese) are segregated into specific grunt-labor roles -- struggle to avoid a catastrophic "blow" resulting from a tunnel leak, while an intrepid girl reporter (Florence Rice) befriends our main men after rescuing a co-worker from an attack of the bends. Naturally, Jumbo (McLaglen) and Shocker (Lowe) jostle for position with the reporter, though it's clear enough that Jumbo's heart ultimately belongs to Amy Hardcastle (Marjorie Rambeau), who runs a tavern catering to sandhogs. Ultimately, Jumbo's recklessness gives him a nearly-crippling case of the bends, which he conceals from his men to keep up their confidence. After all, he doesn't need two good legs for the last part of the process, which requires him to dig away at a wall of dirt with his bare hands, almost like a dog, to force his way into Bickford's tunnel before the hated rival does the opposite. In fact, Bickford gets through first, but is promptly put back through his hole, McLaglen following to deliver the coup de grace.