Yosemite National Park will have cables on Half Dome installed by Thursday, giving hikers long-awaited access to the final stretch of the summit, officials said.

The park puts up the cables each spring, usually the Friday before Memorial Day, and takes them down by mid-October. Visitors use the cables to ascend the last 400 feet of the iconic dome, and permits are required for the climb.

But a blitz of tourists over Memorial Day weekend didn’t have the option of scaling the summit this year due to snow, ice and other hazards on the trail, park officials said. The cable route remained closed for repairs.

This year marks the 100-year anniversary of the cables. The Sierra Club funded their installation in 1919, and the Depression-era Civilian Conservation Corps replaced the original ones 15 years later.

The entire Half Dome hike is about 15 miles with an elevation gain of 4,800 feet. It takes most people 10 to 12 hours to complete the trek, according to park officials. Every year, rangers are called to assist hundreds of people who become injured or fatigued on the trail.

The park offers 300 daily permits to scale Half Dome: 225 for day hikers and 75 for backpackers with multiday wilderness permits.

Permits weren’t required for most of the park’s history, but four deaths in as many years prompted officials in 2010 to cap the number of hikers on Half Dome.

Programmers quickly figured out how to rig the online system, with success rates for weekend permit-seekers as low as 2%.

To level the playing field this year, park officials said they would make an additional 50 permits available each day in a second lottery based on cancellations and no-shows. Hikers apply two days ahead of time and find out the same day whether they won.

An arduous trail and a competitive permit process aren’t the only issues to overcome to successfully hike Half Dome, though.

Many of the complimentary shuttles meant to combat increasing traffic in the park have become overcrowded and fallen into disrepair, leading to long wait times and safety concerns among drivers.

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov