diff --git a/simvue/api/objects/alert/fetch.py b/simvue/api/objects/alert/fetch.py
index 05cc132d..ddda635f 100644
--- a/simvue/api/objects/alert/fetch.py
+++ b/simvue/api/objects/alert/fetch.py
@@ -150,4 +150,6 @@ def get(
                     ),
                 )
             else:
-                raise RuntimeError(f"Unrecognised alert source '{_entry['source']}'")
+                raise RuntimeError(
+                    f"Unrecognised alert source '{_entry['source']}' with data '{_entry}'"
+                )
diff --git a/simvue/api/objects/artifact/base.py b/simvue/api/objects/artifact/base.py
index 9b656297..729fff07 100644
--- a/simvue/api/objects/artifact/base.py
+++ b/simvue/api/objects/artifact/base.py
@@ -31,8 +31,8 @@
 
 Category = typing.Literal["code", "input", "output"]
 
-UPLOAD_TIMEOUT: int = 30
-DOWNLOAD_TIMEOUT: int = 30
+UPLOAD_TIMEOUT_PER_MB: int = 1
+DOWNLOAD_TIMEOUT_PER_MB: int = 1
 DOWNLOAD_CHUNK_SIZE: int = 8192
 
 
@@ -108,7 +108,7 @@ def on_reconnect(self, id_mapping: dict[str, str]) -> None:
         for id, category in _offline_staging.items():
             self.attach_to_run(run_id=id_mapping[id], category=category)
 
-    def _upload(self, file: io.BytesIO) -> None:
+    def _upload(self, file: io.BytesIO, timeout: int, file_size: int) -> None:
         if self._offline:
             super().commit()
             return
@@ -116,6 +116,13 @@ def _upload(self, file: io.BytesIO) -> None:
         if not (_url := self._staging.get("url")):
             return
 
+        if not timeout:
+            timeout = UPLOAD_TIMEOUT_PER_MB * file_size / 1024 / 1024
+
+        self._logger.debug(
+            f"Will wait for a period of {timeout}s for upload of file to complete."
+        )
+
         _name = self._staging["name"]
 
         _response = sv_post(
@@ -123,6 +130,7 @@ def _upload(self, file: io.BytesIO) -> None:
             headers={},
             params={},
             is_json=False,
+            timeout=timeout,
             files={"file": file},
             data=self._init_data.get("fields"),
         )
@@ -325,7 +333,9 @@ def download_content(self) -> typing.Generator[bytes, None, None]:
                 f"Could not retrieve URL for artifact '{self._identifier}'"
             )
         _response = sv_get(
-            f"{self.download_url}", timeout=DOWNLOAD_TIMEOUT, headers=None
+            f"{self.download_url}",
+            timeout=DOWNLOAD_TIMEOUT_PER_MB * self.size / 1024 / 1024,
+            headers=None,
         )
 
         get_json_from_response(
diff --git a/simvue/api/objects/artifact/file.py b/simvue/api/objects/artifact/file.py
index 0bad9447..b2dfd078 100644
--- a/simvue/api/objects/artifact/file.py
+++ b/simvue/api/objects/artifact/file.py
@@ -37,6 +37,7 @@ def new(
         file_path: pydantic.FilePath,
         mime_type: str | None,
         metadata: dict[str, typing.Any] | None,
+        upload_timeout: int | None = None,
         offline: bool = False,
         **kwargs,
     ) -> Self:
@@ -56,6 +57,8 @@ def new(
             the mime type for this file, else this is determined
         metadata : dict[str, Any] | None
             supply metadata information for this artifact
+        upload_timeout : int | None, optional
+            specify the timeout in seconds for upload
         offline : bool, optional
             whether to define this artifact locally, default is False
 
@@ -100,6 +103,6 @@ def new(
             return _artifact
 
         with open(_file_orig_path, "rb") as out_f:
-            _artifact._upload(file=out_f)
+            _artifact._upload(file=out_f, timeout=upload_timeout, file_size=_file_size)
 
         return _artifact
diff --git a/simvue/api/objects/artifact/object.py b/simvue/api/objects/artifact/object.py
index de34ff60..efe1d9fa 100644
--- a/simvue/api/objects/artifact/object.py
+++ b/simvue/api/objects/artifact/object.py
@@ -39,6 +39,7 @@ def new(
         storage: str | None,
         obj: typing.Any,
         metadata: dict[str, typing.Any] | None,
+        upload_timeout: int | None = None,
         allow_pickling: bool = True,
         offline: bool = False,
         **kwargs,
@@ -57,6 +58,8 @@ def new(
             object to serialize and upload
         metadata : dict[str, Any] | None
             supply metadata information for this artifact
+        upload_timeout : int | None, optional
+            specify the timeout in seconds for upload
         allow_pickling : bool, optional
             whether to allow the object to be pickled if no other
             serialization found. Default is True
@@ -119,5 +122,11 @@ def new(
         if offline:
             return _artifact
 
-        _artifact._upload(file=io.BytesIO(_serialized))
+        _file_data = io.BytesIO(_serialized)
+
+        _artifact._upload(
+            file=_file_data,
+            timeout=upload_timeout,
+            file_size=len(_file_data.getbuffer()),
+        )
         return _artifact
diff --git a/simvue/api/request.py b/simvue/api/request.py
index c8a76a31..fff056ed 100644
--- a/simvue/api/request.py
+++ b/simvue/api/request.py
@@ -68,6 +68,7 @@ def post(
     params: dict[str, str],
     data: typing.Any,
     is_json: bool = True,
+    timeout: int | None = None,
     files: dict[str, typing.Any] | None = None,
 ) -> requests.Response:
     """HTTP POST with retries
@@ -102,7 +103,7 @@ def post(
         headers=headers,
         params=params,
         data=data_sent,
-        timeout=DEFAULT_API_TIMEOUT,
+        timeout=timeout,
         files=files,
     )
 
diff --git a/simvue/run.py b/simvue/run.py
index c2419bb7..bc39c620 100644
--- a/simvue/run.py
+++ b/simvue/run.py
@@ -70,7 +70,6 @@
 if typing.TYPE_CHECKING:
     from .factory.dispatch import DispatcherBaseClass
 
-UPLOAD_TIMEOUT: int = 30
 HEARTBEAT_INTERVAL: int = 60
 RESOURCES_METRIC_PREFIX: str = "resources"
 
diff --git a/tests/functional/test_scenarios.py b/tests/functional/test_scenarios.py
index 9b9983c5..1a4042c4 100644
--- a/tests/functional/test_scenarios.py
+++ b/tests/functional/test_scenarios.py
@@ -1,11 +1,66 @@
+import pathlib
 import pytest
 import simvue
 import time
 import contextlib
 import random
+import tempfile
 import threading
 from multiprocessing import Process, Manager
 
+from simvue.api.objects.artifact.fetch import Artifact
+
+
+@pytest.mark.scenario
+@pytest.mark.parametrize(
+    "file_size", (1, 10, 100)
+)
+def test_large_file_upload(file_size: int, create_plain_run: tuple[simvue.Run, dict]) -> None:
+    FILE_SIZE_MB: int = file_size
+    run, _ = create_plain_run
+    run.update_metadata({"file_size_mb": file_size})
+    _file = None
+    _temp_file_name = None
+
+    try:
+        with tempfile.NamedTemporaryFile(mode="w+b", delete=False) as temp_f:
+            temp_f.seek(FILE_SIZE_MB * 1024 * 1024 - 1)
+            temp_f.write(b'\0')
+            temp_f.flush()
+            temp_f.seek(0)
+            temp_f.close()
+        _temp_file_name = temp_f.name
+        _input_file_size = pathlib.Path(f"{_temp_file_name}").stat().st_size
+        run.save_file(file_path=f"{temp_f.name}", category="output", name="test_large_file_artifact")
+
+        run.close()
+
+        client = simvue.Client()
+
+        with tempfile.TemporaryDirectory() as tempd:
+            client.get_artifact_as_file(
+                run_id=run.id,
+                name="test_large_file_artifact",
+                output_dir=tempd
+            )
+
+            _file = next(pathlib.Path(tempd).glob("*"))
+
+            # Assert the returned file size
+            assert _file.stat().st_size == _input_file_size
+    except Exception as e:
+        _run = simvue.Run()
+        _run.reconnect(run.id)
+        _run.set_status("failed")
+        raise e
+    finally:
+        if _file and _file.exists():
+            _file.unlink()
+        if _temp_file_name and (_src := pathlib.Path(_temp_file_name)).exists():
+            _src.unlink()
+        with contextlib.suppress(Exception):
+            Artifact.from_name("test_large_file_artifact", run_id=run.id).delete()
+
 
 @pytest.mark.scenario
 def test_time_multi_run_create_threshold() -> None: