State of loading for the crane as a whole.
| State of loading | Nominal load spectrum factor, Kp | Descriptive definition |
| Q1 Light | 0.5 | Cranes that hoist the safe working load very rarely and normally light loads |
| Q2 Modarate | 0.63 | Cranes that hoist the safe working load fairly frequently ang normally moderate loads |
| Q3 Heavy | 0.8 | Cranes that hoist the safe working load frequently ang normally heavy loads
|
| Q4 Very Heavy | 1 | Cranes that a normally loaded close to safe working load
|
Load spectrum factor can be calculated using the following method.
P1 - load corresponding to cycle C1
Pmax - rated load
C1 , C2 , etc. - No. of cycles which occur at individual lifted loads P1 ,P2 , etc.
Ct - total No. of cycles
Hoist motion hours per day
$$ hoist_{hours_{day}} = {{( hook_{cycles} \cdot hook_{travel} \cdot cycles_{hour} \cdot hours_{operating} ) \over \left({ v_{hoist} \cdot 60 }\right)}} $$
Hoist motion cycles per day
$$ hoist_{cycles_{day}} = {hoist_{hours_{day}} \cdot cycles_{hour}} $$
Total service cycles
$$ crane_{cycles} = {hoist_{cycles_{day}} \cdot hoist_{days} \cdot hoist_{years}} $$
Class of utilisation for the crane as a whole
| Class of utilisation | Max. number of operating cycles | Remarks |
| U1 | 3.2 x 104 | Infrequent use |
| U2 | 6.3 x 104
| Infrequent use
|
| U3 | 1.25 x 105
| Infrequent use
|
| U4 | 2.5 x 105
| Fairly frequent use |
| U5 | 5 x 105 | Frequent use
|
| U6 | 1 x 106
| Very frequent use |
| U7 | 2 x 106
| Continuous or near continuous use |
| U8 | 4 x 106
| Continuous or near continuous use
|
| U9 | > 4 x 106
| Continuous or near continuous use
|
Group classification as a whole
| State of loading | Kp | U1 | U2 | U3 | U4 | U5 | U6 | U7 | U8 | U9 |
| Q1 Light | 0.5 | A1 | A1
| A2
| A3
| A4 | A5 | A6 | A7 | A8 |
| Q2 Moderate | 0.63 | A1
| A2
| A3
| A4
| A5
| A6
| A7
| A8
| A8
|
| Q3 Heavy | 0.8 | A2 | A3
| A4
| A5
| A6
| A7
| A8
| A8
| A8
|
| Q4 Very Heavy | 1 | A3 | A4
| A5
| A6
| A7
| A8
| A8
| A8
| A8
|
Crane classification
