LONDON, Sept 9 (Reuters) - Commuters in London turned to

bikes, buses and boats on Tuesday as a staff strike shut down

the capital's underground "Tube" network for a second day.

With almost no underground trains running until Friday,

demand for shared bike services and river transport surged as

Londoners looked for alternative ways to get to work, causing

longer journeys and crowding on other parts of the transport

network.

The London-based Centre for Economics and Business Research

estimates the strike will have a direct impact on the London

economy of 230 million pounds ($310 million), and cost millions

more indirectly.

Lime, which operates electric bikes across the city, said it

saw a 58% increase in trips during Monday's morning peak

compared with the same period a week earlier.

"Journeys were longer in both distance and duration,

indicating that many riders relied on Lime for their entire

commute rather than just the first or last mile," a Lime

spokesperson said.

Forest, another bike-sharing firm which operates 15,000

e-bikes in London, reported a 100% increase in rides between 7

a.m. (0600 GMT) and 8 a.m. on Monday. It said it expected 60,000

active users throughout the day - more than double its usual

Monday volume of about 27,000.

Uber Boat by Thames Clippers, a river bus service operating

on the Thames, said its services were "busier than usual," with

extra sailings added, including a shuttle between Canary Wharf

and London Bridge.

The strike, called by the RMT union, centres on pay, fatigue

management and shift patterns. Transport for London has offered

a 3.4% pay rise, but the union is pushing for a reduction in

working hours.

Prime Minister Keir Starmer's government, which vowed to

tackle widespread strike action across the economy before it was

elected last July, has called for a resolution.

($1 = 0.7362 pounds)