Sample COGO Ramp-Compound
Spiral
Input Code
| 1 | LOCATE 1 ON CHAIN L STA 10931.71 OFFSET 47 |
| 2 | LOCATE 10 ON CHAIN Y8 STA 3805 |
| 3 | ALI RP1C INC |
| 4 | POT 1 TD N 51 35 56.74 W |
| 5 | POT 2 TL 0 |
| 6 | CUR RP1CTMP TL 0 R 3453 P DEF ? |
| 7 | SPI RP1C1B TL 0 LS 200 |
| 8 | CUR RP1C1 TL 0 R 1000 P DEF ? |
| 9 | SPI RP1C1A TL 0 LS 200 |
| 10 | POT 3 TL 0 |
| 11 | SPI RP1C2B TL 0 LS 200 |
| 12 | CUR RP1C2 TL 0 R 1200 M DEF ? |
| 13 | SPI RP1C2A TL 0 LS 200 |
| 14 | POT 10 TL 300 TD N 10 39 10 E |
| 15 | END ALI RP1C |
| 16 | S CHA RP1C SPI RP1C1B CUR RP1C1 SPI RP1C1A SPI RP1C2B CUR RP1C2 SPI RP1C2A 10 STA 500 |
| 17 | DES CHA RP1C |
Line by Line Code Breakdown
| Line 1 | Locate point 1 on chain -L- station 109+31.71 (SC) offset 47' right. |
| Line 2 | Locate point 10 on chain -Y8- station 38+05.00. This is where RP1C will tie to Y8. |
| Line 3 | Standard Incomplete Alignment Method opening statement with ramp name. |
| Line 4 | Starting at point 1, proceed at a tangent direction ahead for curve L3 (known). |
| Line 5 | Point 2 with tangent of 0'. |
| Line 6 | Temporary offset curve (3500 - 47= 3457) with an unknown positive deflection. Let Geopak solve this for you. |
| Line 7 | Back spiral 1 statement with tangent length equals 0' and length of spiral equals 200'. |
| Line 8 | Curve 1 with tangent length equals 0' R 1000' and an unknown positive deflection. Let Geopak solve this for you. |
| Line 9 | Ahead spiral 1 statement with tangent length equals 0' and length of spiral equals 200'. |
| Line 10 | Point 3 with tangent of 0'. Also Point of Reverse Spiral. |
| Line 11 | Back spiral 2 statement with tangent length equals 0' and length of spiral equals 200'. |
| Line 12 | Curve 2 with tangent length equals 0' R 1200' and an unknown minus deflection. Let Geopak solve this for you. |
| Line 13 | Ahead spiral 2 statement with tangent length equals 0' and length of spiral equals 200'. |
| Line 14 | Point 10 ties alignment RP1C and Y8 together. The 96° skew is calculated from a known -Y8- bearing at tie point. |
| Line 15 | Standard Incomplete Alignment Method closing statement with optional ramp name. |
| Line 16 | Recompile RP1C alignment without the first temporary curve beginning at station 5+00. |
| Line 17 | Describe chain to check the alignment. |
Note that in the above example, I have chosen three deflection angles as my unknown. However, as with any incomplete alignments script, the following combination may be chosen.
- Up to 3 Angles (Deflections)
- Up to 2 Radii
- Up to 2 Directions (Bearings)
- Up to 2 Distances (Tangent Lengths)
A combination of angles to distances to directions to radii is applicabible when valid.
