diff --git a/src/lib/components/ShipEdit/Structure/Hull.svelte b/src/lib/components/ShipEdit/Structure/Hull.svelte
new file mode 100644
index 0000000..3f73838
--- /dev/null
+++ b/src/lib/components/ShipEdit/Structure/Hull.svelte
@@ -0,0 +1,27 @@
+  <ShipItem {...reqs}>
+    <Field label="hull">
+      <input bind:value={rating} type="number" {min} {max} />
+    </Field>
+  </ShipItem>
+
+<script>
+  import { getContext } from "svelte";
+
+  import ShipItem from '$lib/components/ShipItem/index.svelte';
+  import Field from '$lib/components/Field/index.svelte';
+
+  export let rating = 0;
+  export let reqs = {};
+  export let min = 0;
+  export let max = 1;
+
+  const ship = getContext('ship');
+
+  $: ship.dispatch.setHull(rating);
+</script>
+
+<style>
+  input {
+    width: 5em;
+  }
+</style>
diff --git a/src/lib/components/ShipEdit/Structure/index.svelte b/src/lib/components/ShipEdit/Structure/index.svelte
new file mode 100644
index 0000000..99699f6
--- /dev/null
+++ b/src/lib/components/ShipEdit/Structure/index.svelte
@@ -0,0 +1,16 @@
+<Section label="structure">
+    <Hull {...hull}/>
+</Section>
+
+<script>
+  import Section from "$lib/components/Section/index.svelte";
+  import Hull from './Hull.svelte';
+
+  export let hull = {};
+
+  $: console.log(hull);
+
+</script>
+
+<style>
+</style>
diff --git a/src/lib/components/ShipEdit/index.svelte b/src/lib/components/ShipEdit/index.svelte
index c745b75..89dec7a 100644
--- a/src/lib/components/ShipEdit/index.svelte
+++ b/src/lib/components/ShipEdit/index.svelte
@@ -6,12 +6,15 @@
 
 <Propulsion propulsion={$shipState.propulsion}/>
 
+<Structure {...$shipState.structure} />
+
 <script>
     import { getContext } from "svelte";
 
     import Identification from "./Identification/index.svelte";
     import ShipCost from "./ShipCost.svelte";
     import Propulsion from "./Propulsion/index.svelte";
+    import Structure from "./Structure/index.svelte";
 
     const { state: shipState } = getContext("ship");
 </script>
diff --git a/src/lib/components/Hull/Armour/Layer/index.svelte b/src/lib/components/Structure/Armour/Layer/index.svelte
similarity index 100%
rename from src/lib/components/Hull/Armour/Layer/index.svelte
rename to src/lib/components/Structure/Armour/Layer/index.svelte
diff --git a/src/lib/components/Hull/Armour/index.svelte b/src/lib/components/Structure/Armour/index.svelte
similarity index 100%
rename from src/lib/components/Hull/Armour/index.svelte
rename to src/lib/components/Structure/Armour/index.svelte
diff --git a/src/lib/components/Hull/Armour/stories.js b/src/lib/components/Structure/Armour/stories.js
similarity index 100%
rename from src/lib/components/Hull/Armour/stories.js
rename to src/lib/components/Structure/Armour/stories.js
diff --git a/src/lib/components/Hull/Cargo/index.svelte b/src/lib/components/Structure/Cargo/index.svelte
similarity index 100%
rename from src/lib/components/Hull/Cargo/index.svelte
rename to src/lib/components/Structure/Cargo/index.svelte
diff --git a/src/lib/components/Hull/Screens/index.svelte b/src/lib/components/Structure/Screens/index.svelte
similarity index 100%
rename from src/lib/components/Hull/Screens/index.svelte
rename to src/lib/components/Structure/Screens/index.svelte
diff --git a/src/lib/components/Hull/Streamlining/index.svelte b/src/lib/components/Structure/Streamlining/index.svelte
similarity index 100%
rename from src/lib/components/Hull/Streamlining/index.svelte
rename to src/lib/components/Structure/Streamlining/index.svelte
diff --git a/src/lib/components/Hull/index.svelte b/src/lib/components/Structure/index.svelte
similarity index 100%
rename from src/lib/components/Hull/index.svelte
rename to src/lib/components/Structure/index.svelte
diff --git a/src/lib/shipDux/index.js b/src/lib/shipDux/index.js
index 447ee88..c3b1c69 100644
--- a/src/lib/shipDux/index.js
+++ b/src/lib/shipDux/index.js
@@ -5,17 +5,18 @@ import propulsion from "./propulsion/index.js";
 import identification from "./identification.js";
 import { calculateDriveReqs } from './propulsion/drive.js';
 import { ftlReqsReaction } from './propulsion/ftl.js';
+import structure from './structure/index.js';
 
 const dux = new Updux({
   subduxes: {
     identification,
-    propulsion
+    propulsion,
+        structure
   },
   initial: {
     reqs: { cost: 0, mass: 10, usedMass: 0 },
   },
     actions: {
-        setShipMass: null,
     }
 });
 
diff --git a/src/lib/shipDux/structure/hull.js b/src/lib/shipDux/structure/hull.js
new file mode 100644
index 0000000..a91160c
--- /dev/null
+++ b/src/lib/shipDux/structure/hull.js
@@ -0,0 +1,31 @@
+import { Updux } from "updux";
+import u from 'updeep';
+
+import reqs from '../reqs.js';
+
+const dux = new Updux({
+  subduxes: {
+        reqs
+  },
+  initial: {
+     rating: 0, min: 0, max: 0,
+  },
+  actions: {
+    setShipMass: null,
+    setHull: null,
+  }
+});
+export default dux;
+
+dux.setMutation( 'setHull', rating => u({rating,
+    reqs: {
+mass: rating, cost: 2 * rating
+    }}) );
+
+dux.setMutation( 'setShipMass', mass => state => {
+    let {rating} = state;
+    if(rating > mass) rating = mass;
+    const min = Math.ceil(mass/10);
+    if(rating < min) rating = min;
+    return u({max: mass, min, rating}, state);
+})
diff --git a/src/lib/shipDux/structure/index.js b/src/lib/shipDux/structure/index.js
new file mode 100644
index 0000000..e407a17
--- /dev/null
+++ b/src/lib/shipDux/structure/index.js
@@ -0,0 +1,8 @@
+import { Updux } from 'updux';
+
+import hull from './hull.js';
+
+const dux = new Updux({
+    subduxes: { hull }
+});
+export default dux;