diff --git a/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H b/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
index feb90f44a..a735459df 100644
--- a/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
+++ b/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
@@ -148,6 +148,14 @@ public:
                 const intersection::direction dir = intersection::VECTOR
             ) const;
 
+            //- Return contact sphere diameter
+            inline scalar contactSphereDiameter
+            (
+                const point& p,
+                const vector& n,
+                const pointField& meshPoints
+            ) const;
+
             //- Return the triangle
             inline triPointRef tri(const pointField&) const;
 
@@ -167,7 +175,11 @@ public:
 //- Hash specialization for hashing triFace - a commutative hash value.
 //  Hash incrementally.
 template<>
-inline unsigned Hash<triFace>::operator()(const triFace& t, unsigned seed) const
+inline unsigned Hash<triFace>::operator()
+(
+    const triFace& t,
+    unsigned seed
+) const
 {
     // Fortunately we don't need this very often
     const uLabel t0(t[0]);
diff --git a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
index e5cb930ee..9275169c7 100644
--- a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
+++ b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
@@ -288,6 +288,22 @@ inline Foam::pointHit Foam::triFace::ray
 }
 
 
+inline Foam::scalar Foam::triFace::contactSphereDiameter
+(
+    const point& p,
+    const vector& n,
+    const pointField& meshPoints
+) const
+{
+    vector n1 = n/(Foam::mag(n) + SMALL);
+    vector n2 = normal(meshPoints);
+
+    n2 /= Foam::mag(n2) + SMALL;
+
+    return 2*((centre(meshPoints) - p) & n2)/((n1 & n2) - 1.0);
+}
+
+
 inline Foam::triPointRef Foam::triFace::tri(const pointField& points) const
 {
     return triPointRef