Here is the output from the program.

--> Solution found at: 6 trucks.
--> Solution found at: 5 trucks.
--> Solution found at: 4 trucks.
 
<Truck T#1>
       --> Orders = (Order#1 Order#9 )
       --> Tank      = (Tank#1 Tank#2 Tank#3 Tank#4 Tank#5 )
       <Tank#1>
              --> Capacity  = 1000
              --> Type      = [2]
              --> Load      = [500]
              --> Orders    = (Order#9.P2 )
       <Tank#2>
              --> Capacity  = 2000
              --> Type      = [1]
              --> Load      = [2000]
              --> Orders    = (Order#1.P1 )
       <Tank#3>
              --> Capacity  = 3000
              --> Type      = [2]
              --> Load      = [3000]
              --> Orders    = (Order#1.P2 )
       <Tank#4>
              --> Capacity  = 4000
              --> Type      = [1]
              --> Load      = [1000]
              --> Orders    = (Order#9.P1 )
       <Tank#5>
              --> Capacity  = 5000
              --> Type      = [3]
              --> Load      = [5000]
              --> Orders    = (Order#1.P3 )
 
<Truck T#2>
       --> Orders = (Order#2 Order#11 )
       --> Tank      = (Tank#1 Tank#2 Tank#3 Tank#4 Tank#5 )
       <Tank#1>
              --> Capacity  = 1000
              --> Type      = [2]
              --> Load      = [500]
              --> Orders    = (Order#11.P2 )
       <Tank#2>
              --> Capacity  = 2000
              --> Type      = [3]
              --> Load      = [2000]
              --> Orders    = (Order#2.P3 )
       <Tank#3>
              --> Capacity  = 3000
              --> Type      = [2]
              --> Load      = [3000]
              --> Orders    = (Order#2.P2 )
       <Tank#4>
              --> Capacity  = 4000
              --> Type      = [5]
              --> Load      = [4000]
              --> Orders    = (Order#2.P5 )
       <Tank#5>
              --> Capacity  = 5000
              --> Type      = [3]
              --> Load      = [500]
              --> Orders    = (Order#11.P3 )
 
<Truck T#3>
       --> Orders = (Order#3 Order#5 Order#10 )
       --> Tank      = (Tank#1 Tank#2 Tank#3 Tank#4 Tank#5 )
       <Tank#1>
              --> Capacity  = 1000
              --> Type      = [3]
              --> Load      = [500]
              --> Orders    = (Order#5.P3 )
       <Tank#2>
              --> Capacity  = 2000
              --> Type      = [1]
              --> Load      = [2000]
              --> Orders    = (Order#3.P1 )
       <Tank#3>
              --> Capacity  = 3000
              --> Type      = [1]
              --> Load      = [2500]
              --> Orders    = (Order#5.P1 Order#10.P1 )
       <Tank#4>
              --> Capacity  = 4000
              --> Type      = [5]
              --> Load      = [4000]
              --> Orders    = (Order#3.P5 )
       <Tank#5>
              --> Capacity  = 5000
              --> Type      = [5]
              --> Load      = [2000]
              --> Orders    = (Order#5.P5 )
 
<Truck T#4>
       --> Orders = (Order#4 Order#6 Order#7 Order#8 )
       --> Tank      = (Tank#1 Tank#2 Tank#3 Tank#4 Tank#5 )
       <Tank#1>
              --> Capacity  = 1000
              --> Type      = [5]
              --> Load      = [1000]
              --> Orders    = (Order#4.P5 )
       <Tank#2>
              --> Capacity  = 2000
              --> Type      = [2]
              --> Load      = [1000]
              --> Orders    = (Order#8.P2 )
       <Tank#3>
              --> Capacity  = 3000
              --> Type      = [2]
              --> Load      = [3000]
              --> Orders    = (Order#4.P2 Order#6.P2 )
       <Tank#4>
              --> Capacity  = 4000
              --> Type      = [4]
              --> Load      = [2500]
              --> Orders    = (Order#4.P4 Order#6.P4 )
       <Tank#5>
              --> Capacity  = 5000
              --> Type      = [5]
              --> Load      = [4500]
              --> Orders    = (Order#6.P5 Order#7.P5 Order#8.P5 )
 
Number of fails               : 382
Number of choice points       : 403
Number of variables           : 466
Number of constraints         : 696
Reversible stack (bytes)      : 381924
Solver heap (bytes)           : 793372
Solver global heap (bytes)    : 4044
And stack (bytes)             : 4044
Or stack (bytes)              : 4044
Search Stack (bytes)          : 4044
Constraint queue (bytes)      : 26164
Total memory used (bytes)     : 1217636
Running time since creation   : 1.34