(Adds dateline, details on protests, departure schedule)
By Shelby Sebens
PORTLAND, Ore., July 29 (Reuters) - Protestors rappelled offa bridge and formed a kayak flotilla in Portland, Oregon, onWednesday hoping to delay Royal Dutch Shell's Arcticoil exploration this summer by blocking the return of a ship toAlaska that holds emergency equipment.
Greenpeace said 13 protesters lowered themselves from theSt. John's bridge in the early morning and 13 others on thetraffic level of the bridge were assisting them.
"Depending on the weather they can stay there for three tofive days," said Cassady Sharp, a spokeswoman for Greenpeace,which says Arctic drilling could be damaging to populations ofwhales, polar bears and walrus if there is an oil spill.
The danglers have food and water and plan to sleep inhammocks suspended over the Willamette River, which providesshipping access to the Pacific Ocean from Portland.
Several activists also assembled in kayaks and small boatson the river below the bridge, holding a large #ShellNo sign,local broadcaster KOIN reported.
No arrests had been made and the bridge was still open totraffic, police spokesman Pete Simpson said.
The Fennica, an icebreaker Shell is leasing, was set tobegin its journey back to Alaska on Wednesday morning, theprotesters said, citing shipping charts. Its departure schedulehas yet to be determined, boat repair facility Vigor said.
The Fennica had returned to Portland in recent days forrepairs to a three foot (1 meter) gash it suffered in Alaskaearlier this month. The ship holds a capping stack, a piece ofequipment that would help plug a oil well, should one blow out.
Until the Fennica returns to the Chukchi Sea off northernAlaska with this emergency equipment, Shell is not allowed todrill into the oil bearing zone, the Interior Department saidlast week in issuing the final permits for exploration. Any delays could be costly as the explorationseason only lasts until about October, when sea ice returns.
President Barack Obama has tried to strike a balance in theArctic by expanding protected areas of Alaska's Arctic NationalWildlife Refuge this spring. But at the same time his InteriorDepartment is allowing Shell to return to drilling leases thecompany obtained when George W. Bush was president.
"The Fennica will begin its return journey to Alaska oncewe've completed the final preparations," Shell spokesman CurtisSmith said.
Shell hopes to return to the Arctic for the first time since2012, when it experienced a series of mishaps including thegrounding of an oil rig. (Reporting by Shelby Sebens in Portland, Oregon, and TimothyGardner in Washington,; Editing by Eric M. Johnson and SandraMaler)