diff --git a/lib/serialisation/VectorUtils.h b/lib/serialisation/VectorUtils.h
index f5c76b84..53088998 100644
--- a/lib/serialisation/VectorUtils.h
+++ b/lib/serialisation/VectorUtils.h
@@ -30,6 +30,48 @@ namespace Grid {
     typedef typename std::vector<std::vector<typename TensorToVec<T>::type>> type;
   };
 
+  template <typename T>
+  void tensorDim(std::vector<size_t> &dim, const T &t, const bool wipe = true)
+  {
+    if (wipe)
+    {
+      dim.clear();
+    }
+  }
+
+  template <typename T>
+  void tensorDim(std::vector<size_t> &dim, const iScalar<T> &t, const bool wipe = true)
+  {
+    if (wipe)
+    {
+      dim.clear();
+    }
+    tensorDim(dim, t._internal, false);
+  }
+
+  template <typename T, int N>
+  void tensorDim(std::vector<size_t> &dim, const iVector<T, N> &t, const bool wipe = true)
+  {
+    if (wipe)
+    {
+      dim.clear();
+    }
+    dim.push_back(N);
+    tensorDim(dim, t._internal[0], false);
+  }
+
+  template <typename T, int N>
+  void tensorDim(std::vector<size_t> &dim, const iMatrix<T, N> &t, const bool wipe = true)
+  {
+    if (wipe)
+    {
+      dim.clear();
+    }
+    dim.push_back(N);
+    dim.push_back(N);
+    tensorDim(dim, t._internal[0][0], false);
+  }
+
   template <typename T>
   typename TensorToVec<T>::type tensorToVec(const T &t)
   {