Comparing minimum hoisting velocity provisions in two leading standards API Spec. 2C (7th Ed), and EN13852-1:2013.
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| #!/usr/bin/env python | |
| # encoding: utf-8 | |
| """ | |
| crane.py: Offshore crane: min. hoisting velocity | |
| 2016 ckunte | |
| Feb 10, 2016: Conditional API curve fixed | |
| """ | |
| import numpy as np | |
| import matplotlib.pyplot as plt | |
| # -- OFF-BOARD LIFTS -- | |
| # x corresponds to significant wave height (Hsig) | |
| def api2c(): | |
| # -- API Spec. 2C 7th Ed -- | |
| # Min. (required) hoisting velocity, m/s (§5.4.5.2) | |
| cf = 0.3048 # ft to m conversion factor | |
| x1 = np.arange(0.0, 1.83, 0.001) | |
| x2 = np.arange(1.83, 3.0, 0.001) | |
| Vhmin_api1 = (0.033 * cf) + 0.098 * x1 | |
| Vhmin_api2 = 0.067 * (x2 + (3.3 * cf)) | |
| plt.plot(x1, Vhmin_api1, color='blue', linewidth=2) | |
| plt.plot(x2, Vhmin_api2, color='blue', linewidth=2) | |
| plt.xlabel('Hsig (m)') | |
| plt.ylabel('Vhmin (m/s)') | |
| plt.grid(True) | |
| plt.title("API Spec 2C, 7th Edition") | |
| plt.savefig("Vhmin_api.png") | |
| plt.show() | |
| def en13852(): | |
| x = np.arange(0.0, 3.0, 0.001) | |
| # -- EN 13852-1:2013 -- | |
| # Radial displacement (m) of load on vessel deck relative | |
| # to the boom tip shall be taken as follows (§ B.3.2.3): | |
| # Offlead = 2.5 + 1.5 * x | |
| # Radial displacement (m) of load on supply vessel deck relative | |
| # to the boom tip shall be taken as follows (§ B.3.3.3): | |
| # Sidelead = 0.5 * (2.5 + 1.5 * x) | |
| # Table B.2: Load supporting deck velocity, Vd (m/s) | |
| Vd = [0, (3.2 * x / (x + 13.5)), (4.0 * x / (x + 7.0)), \ | |
| (6.0 * x / (x + 8.0)), (5.3 * x / (x + 5.5))] | |
| # Table B.3: Crane boom tip velocity, Vc (m/s) | |
| Vc = [0, (0.25 * x), (0.5 * x)] | |
| # Table B.4: Velocity factor K_H | |
| # K_H structure: [NL & SFR, RC & SFR, NL & MFR, RC & MFR] | |
| K_H = [0.65, 0.50, 0.40, 0.28] | |
| # Hook velocity | |
| # Crane on bottom supported structure | |
| ## Lifting to/from: Barge (No load, Single fall reeving) | |
| VH_f_b_nl_sfr = K_H[0] * (Vd[2]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Single fall reeving) | |
| VH_f_b_rc_sfr = K_H[1] * (Vd[2]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Barge (No load, Multiple fall reeving) | |
| VH_f_b_nl_mfr = K_H[2] * (Vd[2]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Multiple fall reeving) | |
| VH_f_b_rc_mfr = K_H[3] * (Vd[2]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Single fall reeving) | |
| VH_f_sv_nl_sfr = K_H[0] * (Vd[3]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Single fall reeving) | |
| VH_f_sv_rc_sfr = K_H[1] * (Vd[3]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Multiple fall reeving) | |
| VH_f_sv_nl_mfr = K_H[2] * (Vd[3]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Multiple fall reeving) | |
| VH_f_sv_rc_mfr = K_H[3] * (Vd[3]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Single fall reeving) | |
| VH_f_ss_nl_sfr = K_H[0] * (Vd[4]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Single fall reeving) | |
| VH_f_ss_rc_sfr = K_H[1] * (Vd[4]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Multiple fall reeving) | |
| VH_f_ss_nl_mfr = K_H[2] * (Vd[4]**2 + Vc[0]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Multiple fall reeving) | |
| VH_f_ss_rc_mfr = K_H[3] * (Vd[4]**2 + Vc[0]**2)**0.5 | |
| # Crane on semi-submersible | |
| ## Lifting to/from: Barge (No load, Single fall reeving) | |
| VH_semi_b_nl_sfr = K_H[0] * (Vd[2]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Single fall reeving) | |
| VH_semi_b_rc_sfr = K_H[1] * (Vd[2]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Barge (No load, Multiple fall reeving) | |
| VH_semi_b_nl_mfr = K_H[2] * (Vd[2]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Multiple fall reeving) | |
| VH_semi_b_rc_mfr = K_H[3] * (Vd[2]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Single fall reeving) | |
| VH_semi_sv_nl_sfr = K_H[0] * (Vd[3]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Single fall reeving) | |
| VH_semi_sv_rc_sfr = K_H[1] * (Vd[3]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Multiple fall reeving) | |
| VH_semi_sv_nl_mfr = K_H[2] * (Vd[3]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Multiple fall reeving) | |
| VH_semi_sv_rc_mfr = K_H[3] * (Vd[3]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Single fall reeving) | |
| VH_semi_ss_nl_sfr = K_H[0] * (Vd[4]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Single fall reeving) | |
| VH_semi_ss_rc_sfr = K_H[1] * (Vd[4]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Multiple fall reeving) | |
| VH_semi_ss_nl_mfr = K_H[2] * (Vd[4]**2 + Vc[1]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Multiple fall reeving) | |
| VH_semi_ss_rc_mfr = K_H[3] * (Vd[4]**2 + Vc[1]**2)**0.5 | |
| # Crane on FPSO or Drill ship | |
| ## Lifting to/from: Barge (No load, Single fall reeving) | |
| VH_ds_b_nl_sfr = K_H[0] * (Vd[2]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Single fall reeving) | |
| VH_ds_b_rc_sfr = K_H[1] * (Vd[2]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Barge (No load, Multiple fall reeving) | |
| VH_ds_b_nl_mfr = K_H[2] * (Vd[2]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Barge (At rated capacity, Multiple fall reeving) | |
| VH_ds_b_rc_mfr = K_H[3] * (Vd[2]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Single fall reeving) | |
| VH_ds_sv_nl_sfr = K_H[0] * (Vd[3]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Single fall reeving) | |
| VH_ds_sv_rc_sfr = K_H[1] * (Vd[3]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (No load, Multiple fall reeving) | |
| VH_ds_sv_nl_mfr = K_H[2] * (Vd[3]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Supply vessel (At rated capacity, Multiple fall reeving) | |
| VH_ds_sv_rc_mfr = K_H[3] * (Vd[3]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Single fall reeving) | |
| VH_ds_ss_nl_sfr = K_H[0] * (Vd[4]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Single fall reeving) | |
| VH_ds_ss_rc_sfr = K_H[1] * (Vd[4]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Sea surface (No load, Multiple fall reeving) | |
| VH_ds_ss_nl_mfr = K_H[2] * (Vd[4]**2 + Vc[2]**2)**0.5 | |
| ## Lifting to/from: Sea surface (At rated capacity, Multiple fall reeving) | |
| VH_ds_ss_rc_mfr = K_H[3] * (Vd[4]**2 + Vc[2]**2)**0.5 | |
| fig, ax = plt.subplots() | |
| # --- | |
| # Crane on bottom supported structure | |
| # Legend: NL: No load; [S,M]FR: [Single,Multiple] fall reeving | |
| plt.title('Crane on bottom supported structure') | |
| #ax.plot(x, VH_f_b_nl_sfr, label="From Barge (NL, SFR)", linewidth=2) | |
| ax.plot(x, VH_f_b_rc_sfr, label="From Barge (RC, SFR)", linewidth=2) | |
| #ax.plot(x, VH_f_b_nl_mfr, label="From Barge (NL, MFR)", linewidth=2) | |
| ax.plot(x, VH_f_b_rc_mfr, label="From Barge (RC, MFR)", linewidth=2) | |
| # | |
| #ax.plot(x, VH_f_sv_nl_sfr, label="From Supply vessel (NL, SFR)", linewidth=2) | |
| ax.plot(x, VH_f_sv_rc_sfr, label="From Supply vessel (RC, SFR)", linewidth=2) | |
| #ax.plot(x, VH_f_sv_nl_mfr, label="From Supply vessel (NL, MFR)", linewidth=2) | |
| ax.plot(x, VH_f_sv_rc_mfr, label="From Supply vessel (RC, MFR)", linewidth=2) | |
| # | |
| #ax.plot(x, VH_f_ss_nl_sfr, label="From Sea surface (NL, SFR)", linewidth=2) | |
| ax.plot(x, VH_f_ss_rc_sfr, label="From Sea surface (RC, SFR)", linewidth=2) | |
| #ax.plot(x, VH_f_ss_nl_mfr, label="From Sea surface (NL, MFR)", linewidth=2) | |
| ax.plot(x, VH_f_ss_rc_mfr, label="From Sea surface (RC, MFR)", linewidth=2) | |
| # --- | |
| # Crane on semi-submersible | |
| # plt.title('Crane on semi-submersible') | |
| # ax.plot(x, VH_semi_b_nl_sfr, label="From Barge (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_b_rc_sfr, label="From Barge (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_b_nl_mfr, label="From Barge (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_b_rc_mfr, label="From Barge (RC, MFR)", linewidth=2) | |
| # # | |
| # ax.plot(x, VH_semi_sv_nl_sfr, label="From Supply vessel (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_sv_rc_sfr, label="From Supply vessel (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_sv_nl_mfr, label="From Supply vessel (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_sv_rc_mfr, label="From Supply vessel (RC, MFR)", linewidth=2) | |
| # # | |
| # ax.plot(x, VH_semi_ss_nl_sfr, label="From Sea surface (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_ss_rc_sfr, label="From Sea surface (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_ss_nl_mfr, label="From Sea surface (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_semi_ss_rc_mfr, label="From Sea surface (RC, MFR)", linewidth=2) | |
| # --- | |
| # Crane on FPSO / drill ship | |
| # plt.title('Crane on FPSO / drill ship') | |
| # ax.plot(x, VH_ds_b_nl_sfr, label="From Barge (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_b_rc_sfr, label="From Barge (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_b_nl_mfr, label="From Barge (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_b_rc_mfr, label="From Barge (RC, MFR)", linewidth=2) | |
| # # | |
| # ax.plot(x, VH_ds_sv_nl_sfr, label="From Supply vessel (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_sv_rc_sfr, label="From Supply vessel (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_sv_nl_mfr, label="From Supply vessel (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_sv_rc_mfr, label="From Supply vessel (RC, MFR)", linewidth=2) | |
| # # | |
| # ax.plot(x, VH_ds_ss_nl_sfr, label="From Sea surface (NL, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_ss_rc_sfr, label="From Sea surface (RC, SFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_ss_nl_mfr, label="From Sea surface (NL, MFR)", linewidth=2) | |
| # ax.plot(x, VH_ds_ss_rc_mfr, label="From Sea surface (RC, MFR)", linewidth=2) | |
| # --- | |
| ax.legend(loc=0) | |
| ax.set_xlabel('Hsig (m)') | |
| ax.set_ylabel('Vhmin (m/s)') | |
| plt.grid(True) | |
| plt.title("EN13852-1:2013") | |
| plt.savefig("Vhmin_en_ds_nl_rc_sfr_mfr.png") | |
| plt.show() | |
| if __name__ == '__main__': | |
| print "Plot min.required hoisting velocity:" | |
| print "Choose a Standard:" | |
| print " 1 - API Spec 2C, 7th Ed." | |
| print " 2 - EN13852-1:2013" | |
| print " 0 - Exit" | |
| standard = input("Standard to use: ") | |
| if standard == 1: | |
| api2c() | |
| if standard == 2: | |
| en13852() |
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