Figure 1
The two H2 fuel cell hybrid buses of the KIT shuttle in front of the H2 refueling station at KIT.
Figure 2
The seven Type III hydrogen storage tanks in the roof of a H2 shuttle bus.
Table 1
Main properties of the shuttle bus hydrogen tanks (Luxfer Cylinders, 2026).
| PARAMETER | SPECIFICATION |
|---|---|
| Manufacturer | Luxfer Dynecell |
| Model/Type | 3W205H350 (Type 3) |
| Technology | Al liner with carbon fiber wrapping |
| Diameter [mm] | 415 |
| Length [mm] | 2110 |
| Weight [kg] | 95 |
| Water Volume [L] | 205 |
| Service Pressure [MPa] | 35 |
| H2 Storage capacity [kg] | 4.9 |
| Certification | EC79/ECE R134 |
Figure 3
Photo and schematic sketch of the KIT H2 refueling station for the KIT shuttle buses.
Table 2
Number of refueling and operating cycles for the tanks and valves of both KIT H2 shuttle buses during their daily service.
| SERVICE | REFUELING CYCLE | OPERATING CYCLE | SERVICE | REFUELING CYCLE | OPERATING CYCLE |
|---|---|---|---|---|---|
| Full day | Rush hour | ||||
| Service start | 1 | Start service 1 | 1 | ||
| Refueling stop 1 | 1 | End service 1 | |||
| Refueling stop 2 | 2 | 2 | Start service 2 | ||
| Refueling stop | 1 | 2 | |||
| Service end | 3 | End service 2 | 3 | ||
Table 3
Total number of refueling and operating cycles for the tanks and valves determined for both KIT H2 shuttle buses.
| OPERATION | BUS 1064 | BUS 1068 | ALLOWED: TANK | ALLOWED: SYSTEM |
|---|---|---|---|---|
| Refueling cycles | 1,289 | 1,354 | 5,000 | |
| Operating cycles | 2,289 | 2,268 | 10,000 |
Figure 4
Sketch of the pressure vessel test facility at KIT.
Figure 5
Example of pressure and temperature readings of a test (top) and detail of measurements (bottom) with illustration of the test evaluation.
Table 4
Summary of pressure vessel test results for both KIT H2 shuttle buses.
| BUS 1064 | BUS 1068 | ||||||
|---|---|---|---|---|---|---|---|
| TANK # | SERIAL # | Δpperm | Δptest | TANK # | SERIAL # | Δpperm | Δptest |
| 1 | R7241 | 5.25 | 1.303 | 1 | R7429 | 5.25 | 2.518 |
| 2 | R9492 | 5.25 | 2.373 | 2 | R7436 | 5.25 | 3.016 |
| 3 | R9507 | 5.25 | 2.156 | 3 | R9500 | 5.25 | 2.719 |
| 4 | R5253 | 5.25 | 1.696 | 4 | R9504 | 5.25 | 1.814 |
| 5 | R7431 | 5.25 | 2.134 | 5 | R7397 | 5.25 | 2.350 |
| 6 | R7395 | 5.25 | 2.638 | 6 | R7409 | 5.25 | 1.360 |
| 7 | R7398 | 5.25 | 2.399 | 7 | R7393 | 5.25 | 2.310 |