diff --git a/swash/processing/read_swash.py b/swash/processing/read_swash.py
index 53c82a9..2eec6b5 100644
--- a/swash/processing/read_swash.py
+++ b/swash/processing/read_swash.py
@@ -13,11 +13,8 @@ class ReadSwash:
 
     @classmethod
     def read_nohead(cls, path):
-        with tempfile.TemporaryFile() as tmpfile:
-            with open(path) as file:
-                subprocess.run(("tr", "-d", "\n"), stdin=file, stdout=tmpfile)
-            tmpfile.seek(0)
-            return np.loadtxt(tmpfile)
+        subprocess.run(("sed", "-i", "s/ /\n/g", path))
+        return np.loadtxt(path)
 
     def read_time(self, path):
         self._t = np.unique(self.read_nohead(path))