Glacier Boats of  Alaska LLC

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Glacier Boats of Alaska LLC - Planing Analysis
General Information
December 06, 2005 10:22:15 PM
Company Project Description
Glacier Boats of Alaska LLC Great Alaskan 26

Condition Information
Prediction Parameters
Method: Savitsky Speed: Check Hull: Check
Design Margin 5 % Water Type Salt
Design Speed 19.000 knots Water Density 0.037 pounds/inches^3
OPC 70 % Water Viscosity 0.00184188 inches^2/s
Vessel Data
Max planing length 279.810 inches LCG fwd transom 99.976 inches
Max planing beam 77.680 inches VCG above origin 27.280 inches
Displacement bare 3,800.000 pounds
Parameter Range Check
LCG/Bch [0.6 - 3] 1.290 Deadrise mid-length [0 - 30] 1,383.970 deg
Fn(Bch)-max [1.43 - 13] 2.220 CLB-max [0 - 0.5] 0.090
Thrust Line
Shaft angle to BL 0.000 deg LCE fwd transom -25.024 inches
VCE above origin -7.000 inches

Drag Results
Drag Prediction
Speed (knots) Fv Trim (deg) 5Rbare (pound) 5Rtotal (pound) 5PEtotal (horsepower) 5PBtotal (horsepower)
7.000 1.050 2.790 378.550 397.480 8.540 12.200
8.000 1.210 3.170 441.970 464.070 11.390 16.271
9.000 1.360 3.580 478.400 502.320 13.870 19.814
10.000 1.510 3.980 501.730 526.810 16.170 23.100
11.000 1.660 4.330 518.030 543.930 18.360 26.229
12.000 1.810 4.590 527.950 554.350 20.410 29.157
13.000 1.960 4.740 532.010 558.610 22.290 31.843
14.000 2.110 4.780 532.270 558.890 24.010 34.300
15.000 2.260 4.740 529.770 556.260 25.610 36.586
16.000 2.410 4.630 525.960 552.260 27.120 38.743
17.000 2.560 4.480 523.360 549.530 28.670 40.957
18.000 2.710 4.300 521.460 547.530 30.240 43.200
19.000 2.860 4.120 521.650 547.730 31.940 45.629
20.000 3.010 3.930 523.720 549.900 33.750 48.214
21.000 3.160 3.760 528.060 554.470 35.730 51.043
22.000 3.310 3.580 534.300 561.020 37.880 54.114
23.000 3.470 3.410 542.420 569.540 40.200 57.429
24.000 3.620 3.250 552.370 579.980 42.720 61.029
25.000 3.770 3.100 564.230 592.450 45.450 64.929
26.000 3.920 2.960 577.810 606.700 48.410 69.157
27.000 4.070 2.820 593.040 622.690 51.590 73.700
28.000 4.220 2.700 609.730 640.220 55.010 78.586
29.000 4.370 2.580 628.260 659.670 58.710 83.871
30.000 4.520 2.470 648.120 680.530 62.650 89.500
31.000 4.670 2.370 669.250 702.710 66.850 95.500
32.000 4.820 2.270 691.680 726.260 71.320 101.886
33.000 4.970 2.180 715.670 751.450 76.100 108.714
34.000 5.120 2.100 740.810 777.850 81.160 115.943
35.000 5.270 2.020 767.090 805.440 86.510 123.586
36.000 5.420 1.940 794.670 834.400 92.180 131.686
37.000 5.570 1.870 823.320 864.480 98.160 140.229
38.000 5.730 1.800 853.000 895.650 104.440 149.200
39.000 5.880 1.740 883.900 928.090 111.070 158.671
40.000 6.100 1.680 914.800 964.790 119.570 168.473
Speed (knots) Fn(Bch) Rbare/W Porpoising Eff planing beam (inches) Eff deadrise (deg) Prediction Check
7.000 0.820 0.100 Stable 77.300 12.460 See note=1,2,3
8.000 0.940 0.116 Stable 77.300 12.460 See note=2
9.000 1.060 0.126 Stable 77.290 12.450 OK
10.000 1.170 0.132 Stable 77.280 12.440 OK
11.000 1.290 0.136 Stable 77.270 12.440 OK
12.000 1.410 0.139 Stable 77.270 12.430 OK
13.000 1.520 0.140 Stable 77.270 12.430 OK
14.000 1.640 0.140 Stable 77.270 12.430 OK
15.000 1.760 0.139 Stable 77.270 12.430 OK
16.000 1.880 0.138 Stable 77.270 12.430 OK
17.000 1.990 0.138 Stable 77.270 12.440 OK
18.000 2.110 0.137 Stable 77.280 12.440 OK
19.000 2.230 0.137 Stable 77.280 12.440 OK
20.000 2.340 0.138 Stable 77.280 12.440 OK
21.000 2.460 0.139 Stable 77.280 12.440 OK
22.000 2.580 0.141 Stable 77.280 12.440 OK
23.000 2.700 0.143 Stable 77.280 12.440 OK
24.000 2.810 0.145 Stable 77.280 12.440 OK
25.000 2.930 0.149 Stable 77.280 12.440 OK
26.000 3.050 0.152 Stable 77.280 12.440 OK
27.000 3.160 0.156 Stable 77.280 12.440 OK
28.000 3.280 0.161 Stable 77.280 12.440 OK
29.000 3.400 0.165 Stable 77.280 12.440 OK
30.000 3.520 0.171 Stable 77.280 12.440 OK
31.000 3.630 0.176 Stable 77.280 12.440 OK
32.000 3.750 0.182 Stable 77.280 12.440 OK
33.000 3.870 0.188 Stable 77.280 12.440 OK
34.000 3.980 0.195 Stable 77.280 12.440 OK
35.000 4.100 0.202 Stable 77.280 12.440 OK
36.000 4.220 0.209 Stable 77.270 12.440 OK
37.000 4.340 0.217 Stable 77.270 12.430 OK
38.000 4.450 0.225 Stable 77.270 12.430 OK
39.000 4.570 0.233 Stable 77.270 12.430 OK
40.000 4.600 0.233 Stable 77.270 12.430 See note=4
General Notes
Rbare is the predicted bare hull resistance. Rtotal is the predicted total resistance which includes the user-specified design margin.
PEtotal is predicted total effective power. It is the power that the propeller must deliver to the water for the specified speed. Required engine power will be substantially higher (sometimes as much as twice the effective power) because it must account for the propulsive efficiency.
A Sensitivity index with a higher value has a greater influence on drag. Sensitivity values greater than 1.0 are considered significant.
Prediction Check Notes
1. A wetted keel length greater than the boat length indicates that the boat is running at small trim and the bow will be immersed. In this condition, the prismatic analysis of the Savitsky prediction will be unreliable and can significantly under-predict the actual drag. However, as this condition typically occurs at pre-planing speeds, the internal hump speed correction accounts for this in the prediction of drag. There is no correction for trim.
2. The Froude number based on chine beam (FnBch) is a good indicator of the development of the spray root and the magnitude of the planing lift coefficient. Results for speeds outside of the Savitsky data set (most often for low speeds below the range) may be unreliable.
3. The lift coefficient (CLb) is a ratio of displacement to the square of speed and chine beam, with a correction for deadrise. This coefficient is a measure of the weight loading for the given planing geometry. We caution against using this method for hulls that produce this data range error.
4. The original testing of the models used in the Savitsky analysis were limited to a given range of trim values. Predicted trim values that are beyond the range of the original data set may be unreliable.
5. Rbare, Rtotal, PEtotal, and PBtotal do not  include the affects of parasitic drag such as that from keel skegs, motor lower units, etcetera and are therefore conservatively low.