The Purple Line Extension Section 1 Tunnel Boring Machines (TBMs), Elsie and Soyeon, are currently digging under Wilshire Bl. They will construct two parallel tunnels to create a seamless connection from the current Purple Line terminus at Wilshire/Western Station in Koreatown to three new stations located at Wilshire/La Brea, Wilshire/Fairfax and Wilshire/La Cienega.
Elsie and Soyeon are responsible for building 17,845 linear feet of tunnels to create approximately 3.9 miles of new subway. They have completed Reach 1 and 2 and are on their way to completing Reach 3.
Harriet and Ruth, the Purple Line Extension Section 2 TBMs, will be building the connection between the Wilshire/La Cienega and Wilshire/Rodeo Stations in Beverly Hills and the Century City/Constellation Station. They will build approximately 2.6 miles of new subway and will be creating 13,630 linear feet of tunnels. Harriet and Ruth are expected to start tunneling Spring 2020.
The last two sets of TBMs for Purple Line Extension Section 3 are on their way to Los Angeles. They will be building the tunnels between the VA Hospital Campus in West LA and Westwood/UCLA. The TBMs which have not yet been named yet will be adding the last 2.56 miles of new subway and will be creating 13,461 linear feet of tunnels. There is currently an Art and Naming contest to honor the two machines before they are put to work. The TBMs are anticipated to start their tunneling journey Winter 2021.
Along the way, all TBMs will encounter different soil conditions. The tunnel crown will always be at least 20 feet or more under the subsurface water table.
In terms of geology, tunnels will be bored through two types of geological formations: San Pedro and Fernando.
Tunneling Statistics
Progress is measured in total linear feet traveled.
Section 1 Tunneling
|
Reach |
Linear Feet |
Location |
|---|---|---|
|
1 |
9,570 |
La Brea Bl to Western Av |
|
2 |
4,440 |
La Brea Bl to Fairfax Av |
|
3 |
3,280 |
Fairfax Av to La Cienega Bl |
|
4 |
555 |
La Cienega Bl to tail track west of La Cienega Bl |
Section 2 Tunneling
|
Reach |
Linear Feet |
Location |
|---|---|---|
|
4 |
6,610 |
Reeves Dr to La Cienega Bl |
|
5 |
7,020 |
Constellation Bl to Reeves Dr |
Section 3 Tunneling
|
Reach |
Linear Feet |
Location |
|---|---|---|
|
6 |
7,589 |
VA Hospital Campus to Wilshire Bl |
|
7 |
5,872 |
Wilshire Bl to Constellation Bl |