Ramps - the ramp system connects many of the levels below the 4850. Adding two zeroes to the first two numbers yields the level below the surface.
48A1 | 48A2 | 48A3 | 48A4 | 48A5 | 48A6 | 48A7 | 50A1 | 50A2 | 50A3 |
51A1 | 51A2 | 51A3 | 51B | 53A | 53MM | 54A | 54B1 | 54B2 | 54C1 |
54C2 | 56A | 56B1 | 56B2 | 56B3 | 56C1 | 56C2 | 57A | 57B1 | 57B2 |
57B3 | 57B4 | 59A | 59B1 | 59B2 | 59C | 60A1 | 60A2 | 60B1 | 60B2 |
60C | 62A1 | 62A2 | 62B1 | 62B2 | 63A1 | 63A2 | 63A3 | 63B1 | 63B2 |
63C1 | 63C2 | 63C3 | 65A | 65B1 | 65B2 | 65C1 | 65C2 | 65C3 | 65C4 |
65D2 | 66A1 | 66A2 | 66A3 | 66B1 | 66B2 | 66C1 | 66C2 | 68A1 | 68A2 |
68A3 | 68B1 | 68B2 | 68B3 | 68C1 | 68C2 | 68C3 | 69A1 | 69A2 | 69A3 |
69A4 | 69B1 | 69B2 | 69C1 | 69C2 | 71A1 | 71A2 | 71A3 | 71B1 | 71B2 |
71B3 | 72A1 | 72A2 | 72A3 | 72A4 | 72B1 | 72B2 | 72B3 | 74A1 | 74A2 |
74A3 | 74A4 | 74A5 | 74A6 | 74B1 | 74B2 | 74B3 | 74B4 | 75A1 | 75A2 |
75A3 | 75B1 | 75B2 | 77A1 | 77A2 | 77B | 78A1 | 78A2 | 80A | 81A1 |
81A2 |