{"id":1848,"date":"2024-07-31T11:15:12","date_gmt":"2024-07-31T11:15:12","guid":{"rendered":"https:\/\/svestudy.com\/?page_id=1848"},"modified":"2025-05-11T10:54:39","modified_gmt":"2025-05-11T10:54:39","slug":"ame-unit-7-q3","status":"publish","type":"page","link":"https:\/\/svestudy.com\/?page_id=1848","title":{"rendered":"AME Unit 7 Q3"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1021\" height=\"195\" src=\"https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-330.png\" alt=\"\" class=\"wp-image-6164\" srcset=\"https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-330.png 1021w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-330-300x57.png 300w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-330-768x147.png 768w\" sizes=\"auto, (max-width: 1021px) 100vw, 1021px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">With reference to the cathodic protection of hull fittings:<br>(a) explain how sacrificial anodes achieve this;(2)<br>(b) state where sacrificial anodes would be fitted and why;(4)<br>(c) describe an impressed current system, stating the principle on which it works.(4)<\/p>\n\n\n<div class=\"wp-block-ub-content-toggle wp-block-ub-content-toggle-block\" id=\"ub-content-toggle-block-81814248-9685-40ca-9608-1e06aefc8d07\" data-mobilecollapse=\"true\" data-desktopcollapse=\"true\" data-preventcollapse=\"false\" data-showonlyone=\"false\">\n<div class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; \" id=\"ub-content-toggle-panel-block-1ab3a0e3-f67d-40b0-902d-d05561fdd8e7\">\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-0-81814248-9685-40ca-9608-1e06aefc8d07\" tabindex=\"0\">\n\t\t\t<p class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-81814248-9685-40ca-9608-1e06aefc8d07\" style=\"color: #000000; \">Sacrificial Anodes: A Shield Against Corrosion<\/p>\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"><span class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"><\/span><\/div>\n\t\t<\/div>\n\t\t\t<div role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-0-81814248-9685-40ca-9608-1e06aefc8d07\">\n\n<p class=\"wp-block-paragraph\"><strong>Sacrificial anodes<\/strong> are a common method of cathodic protection used to prevent corrosion on underwater metal structures, including ship hulls and their fittings. \u00a0<a href=\"https:\/\/cathwell.com\/industries\/floating-offshore-units\/sacrificial-anodes\/#:~:text=Sacrificial%20anodes%20in%20zinc%20or,water%20tanks%20and%20cargo%20tanks.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/cathwell.com\/industries\/floating-offshore-units\/sacrificial-anodes\/#:~:text=Sacrificial%20anodes%20in%20zinc%20or,water%20tanks%20and%20cargo%20tanks.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Anodes for hull &#8211; Cathwell <\/a><a href=\"https:\/\/cathwell.com\/industries\/floating-offshore-units\/sacrificial-anodes\/#:~:text=Sacrificial%20anodes%20in%20zinc%20or,water%20tanks%20and%20cargo%20tanks.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/cathwell.com\/industries\/floating-offshore-units\/sacrificial-anodes\/#:~:text=Sacrificial%20anodes%20in%20zinc%20or,water%20tanks%20and%20cargo%20tanks.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How Sacrificial Anodes Work:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Material Selection:<\/strong> Anodes are made from metals more reactive than the metal to be protected (often zinc, aluminum, or magnesium). \u00a0 <a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Sacrificial Anodes: Zinc Protecting Parts from Salt Water &#8211; Belmont Metals <\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\">www.belmontmetals.com<\/a><a href=\"https:\/\/www.belmontmetals.com\/sacrificial-anodes-zinc-protecting-parts-from-salt-water\/#:~:text=A%20sacrificial%20anode%20consists%20of,introduced%20into%20the%20electrolyte%20current.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Electrical Connection:<\/strong> The anodes are electrically connected to the hull. \u00a0 <a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Zinc Sacrificial Anodes &#8211; Protecting Ships &#8211; Hindustan Zinc <\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\">www.hzlindia.com<\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Sacrificial%20Anodes%20are%20linked%20electrically,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Corrosion Process:<\/strong> When immersed in seawater, the anode metal corrodes preferentially, acting as a sacrificial material. \u00a0 <a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\">1. How Do Sacrificial Anodes Work? &#8211; BoatUS <\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\">www.boatus.com<\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=The%20electrons%20that%20make%20up,metal%20ions%20%E2%80%94%20to%20the%20seawater.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Cathodic Protection:<\/strong> As the anode corrodes, it releases electrons, creating a protective current that flows to the hull, preventing it from corroding. \u00a0 <a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\">1. The Importance of Cathodic Protection for Ship Hulls with Sacrificial Anodes <\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\">corrosion-group.com<\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20hull%20acts%20as%20the,preventing%20the%20hull%20from%20corroding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Key Benefits:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Simplicity:<\/strong> Relatively easy to install and maintain.<\/li>\n\n\n\n<li class=\"\"><strong>Cost-Effective:<\/strong> Often a more economical option compared to other corrosion protection methods.<\/li>\n\n\n\n<li class=\"\"><strong>Reliable:<\/strong> Provides consistent protection when properly installed and maintained.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Image of Sacrificial Anodes:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/www.marineinsight.com\/tech\/understanding-sacrificial-anodes-on-ships\/\">Opens in a new window<\/a><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/www.marineinsight.com\/tech\/understanding-sacrificial-anodes-on-ships\/\">www.marineinsight.com<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">sacrificial anodes on a ship hull<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By acting as a sacrificial metal, anodes protect the hull and its fittings from galvanic corrosion, extending their lifespan and reducing maintenance costs. \u00a0<a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20electrical%20current%20flows%20from,current%20needed%20to%20prevent%20corrosion.&amp;Sacrificial%20anodes%20are%20one%20of,of%20cathodic%20protection%20for%20ships.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20electrical%20current%20flows%20from,current%20needed%20to%20prevent%20corrosion.&amp;Sacrificial%20anodes%20are%20one%20of,of%20cathodic%20protection%20for%20ships.\" target=\"_blank\" rel=\"noreferrer noopener\">1. The Importance of Cathodic Protection for Ship Hulls with Sacrificial Anodes <\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20electrical%20current%20flows%20from,current%20needed%20to%20prevent%20corrosion.&amp;Sacrificial%20anodes%20are%20one%20of,of%20cathodic%20protection%20for%20ships.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/the-importance-of-cathodic-protection-for-ship-hulls-with-sacrificial-anodes\/#:~:text=The%20electrical%20current%20flows%20from,current%20needed%20to%20prevent%20corrosion.&amp;Sacrificial%20anodes%20are%20one%20of,of%20cathodic%20protection%20for%20ships.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n<\/div>\n\t\t<\/div>\n\n<div class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; \" id=\"ub-content-toggle-panel-block-1ab3a0e3-f67d-40b0-902d-d05561fdd8e7\">\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-1-81814248-9685-40ca-9608-1e06aefc8d07\" tabindex=\"0\">\n\t\t\t<p class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-81814248-9685-40ca-9608-1e06aefc8d07\" style=\"color: #000000; \">Placement of Sacrificial Anodes on a Vessel<\/p>\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"><span class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"><\/span><\/div>\n\t\t<\/div>\n\t\t\t<div role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-1-81814248-9685-40ca-9608-1e06aefc8d07\">\n\n<p class=\"wp-block-paragraph\">Sacrificial anodes are strategically placed on a vessel to provide optimal protection against galvanic corrosion. Common locations include: \u00a0<a href=\"https:\/\/corrosion-group.com\/resources\/cathodic-protection\/galvanic-corrosion\/#:~:text=This%20strategic%20deployment%20of%20sacrificial,by%20electrochemical%20principles%20and%20engineered\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/corrosion-group.com\/resources\/cathodic-protection\/galvanic-corrosion\/#:~:text=This%20strategic%20deployment%20of%20sacrificial,by%20electrochemical%20principles%20and%20engineered\" target=\"_blank\" rel=\"noreferrer noopener\">1. Galvanic Corrosion &#8211; Cathodic Protection <\/a><a href=\"https:\/\/corrosion-group.com\/resources\/cathodic-protection\/galvanic-corrosion\/#:~:text=This%20strategic%20deployment%20of%20sacrificial,by%20electrochemical%20principles%20and%20engineered\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/corrosion-group.com\/resources\/cathodic-protection\/galvanic-corrosion\/#:~:text=This%20strategic%20deployment%20of%20sacrificial,by%20electrochemical%20principles%20and%20engineered\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Hull:<\/strong> Anodes are often attached to the hull&#8217;s underside, particularly around the keel, rudder, and propeller. \u00a0 <a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Zinc Sacrificial Anodes &#8211; Protecting Ships &#8211; Hindustan Zinc <\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\">www.hzlindia.com<\/a><a href=\"https:\/\/www.hzlindia.com\/ask_for_zinc\/zinc-sacrificial-anodes-protecting-ships\/#:~:text=Zinc%20coating%20being%20used%20for,the%20ship's%20body%20and%20systems.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Shafts and struts:<\/strong> These components are susceptible to corrosion due to their exposure to seawater.<\/li>\n\n\n\n<li class=\"\"><strong>Sea chests:<\/strong> Anodes are placed within sea chests to protect the internal components.<\/li>\n\n\n\n<li class=\"\"><strong>Cooling water systems:<\/strong> Anodes can be installed in the cooling water system to protect heat exchangers and other components. \u00a0 <a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\">1. How Do Sacrificial Anodes Work? &#8211; BoatUS <\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\">www.boatus.com<\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Outdrives and sterndrives:<\/strong> These components often require multiple anodes due to their complex metal composition. \u00a0 <a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\">1. How Do Sacrificial Anodes Work? &#8211; BoatUS <\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\">www.boatus.com<\/a><a href=\"https:\/\/www.boatus.com\/expert-advice\/expert-advice-archive\/2012\/july\/how-do-sacrificial-anodes-work#:~:text=Outdrives,are%20more%20than%20half%20depleted.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The specific placement of anodes depends on several factors, including:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\">Vessel size and type<\/li>\n\n\n\n<li class=\"\">Material composition of the hull and components<\/li>\n\n\n\n<li class=\"\">Operating environment (freshwater, saltwater, or brackish water)<\/li>\n\n\n\n<li class=\"\">Severity of corrosion risk<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">By carefully considering these factors, it is possible to optimize the protection provided by sacrificial anodes.<\/p>\n\n<\/div>\n\t\t<\/div>\n\n<div class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; \" id=\"ub-content-toggle-panel-block-1ab3a0e3-f67d-40b0-902d-d05561fdd8e7\">\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-2-81814248-9685-40ca-9608-1e06aefc8d07\" tabindex=\"0\">\n\t\t\t<p class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-81814248-9685-40ca-9608-1e06aefc8d07\" style=\"color: #000000; \">Impressed Current System<\/p>\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"><span class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"><\/span><\/div>\n\t\t<\/div>\n\t\t\t<div role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-2-81814248-9685-40ca-9608-1e06aefc8d07\">\n\n<p class=\"wp-block-paragraph\">An impressed current system is a method of cathodic protection that uses an external power source to protect a metal structure from corrosion. Unlike sacrificial anode systems, which rely on the corrosion of a sacrificial metal to protect the structure, impressed current systems provide a continuous electrical current to the structure.<\/p>\n\n\n\n<h3 class=\" wp-block-heading\">Principle of Operation<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The system consists of:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Anodes:<\/strong> Typically made of inert materials like graphite or platinum-coated titanium, these are submerged in the electrolyte (seawater).<\/li>\n\n\n\n<li class=\"\"><strong>Rectifier:<\/strong> Converts AC power to DC power, which is necessary for the system to operate.<\/li>\n\n\n\n<li class=\"\"><strong>Reference Electrode:<\/strong> Monitors the potential of the protected structure.<\/li>\n\n\n\n<li class=\"\"><strong>Power Cables:<\/strong> Connect the rectifier, anodes, and the structure.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The rectifier supplies a direct current to the anode, causing it to release electrons. These electrons flow through the seawater to the metal structure, protecting it from corrosion by making it the cathode in the electrochemical process. The reference electrode measures the potential of the protected structure and provides feedback to the rectifier to adjust the current output as needed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key advantages of impressed current systems:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\">Highly effective in protecting large structures<\/li>\n\n\n\n<li class=\"\">Precise control over the protection level<\/li>\n\n\n\n<li class=\"\">Can be used in environments with high corrosion rates<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">By applying a controlled electrical current, impressed current systems provide a reliable and efficient method of corrosion protection for marine structures.<\/p>\n\n<\/div>\n\t\t<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>With reference to the cathodic protection of hull fittings:(a) explain how sacrificial anodes achieve this;(2)(b) state where sacrificial anodes would be fitted and why;(4)(c) describe an impressed current system, stating the principle on which it works.(4)<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"templates\/template-full-width.php","meta":{"nf_dc_page":"","footnotes":""},"class_list":["post-1848","page","type-page","status-publish","hentry"],"featured_image_src":null,"_links":{"self":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/1848","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/svestudy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1848"}],"version-history":[{"count":5,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/1848\/revisions"}],"predecessor-version":[{"id":9812,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/1848\/revisions\/9812"}],"wp:attachment":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1848"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}