diff --git a/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixture.cs b/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixture.cs
new file mode 100644
index 00000000..ede98c32
--- /dev/null
+++ b/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixture.cs
@@ -0,0 +1,120 @@
+using Akka.Actor;
+using Akka.Cluster;
+using Akka.Configuration;
+using ZB.MOM.WW.ScadaBridge.ClusterInfrastructure;
+using ZB.MOM.WW.ScadaBridge.Host;
+using ZB.MOM.WW.ScadaBridge.Host.Actors;
+
+namespace ZB.MOM.WW.ScadaBridge.IntegrationTests.Cluster;
+
+/// <summary>
+/// Forms a REAL two-node Akka cluster in-process from the production
+/// BuildHocon output. NodeA is always started first (=> oldest member /
+/// singleton host). CrashNode() terminates a node WITHOUT cluster-leave
+/// (coordinated-shutdown by-terminate disabled on both nodes) to simulate
+/// a hard crash — the scenario review 01 found untested.
+/// </summary>
+public sealed class TwoNodeClusterFixture : IAsyncDisposable
+{
+    public ActorSystem NodeA { get; private set; } = null!;
+    public ActorSystem NodeB { get; private set; } = null!;
+    public int PortA { get; private set; }
+    public int PortB { get; private set; }
+
+    public static async Task<TwoNodeClusterFixture> StartAsync(
+        string role = "Central", TimeSpan? stableAfter = null)
+    {
+        var f = new TwoNodeClusterFixture();
+        f.PortA = GetFreeTcpPort();
+        f.PortB = GetFreeTcpPort();
+        f.NodeA = f.StartNode(f.PortA, role, stableAfter);
+        await WaitForMembersUp(f.NodeA, 1, TimeSpan.FromSeconds(20));
+        f.NodeB = f.StartNode(f.PortB, role, stableAfter);
+        await WaitForMembersUp(f.NodeA, 2, TimeSpan.FromSeconds(20));
+        await WaitForMembersUp(f.NodeB, 2, TimeSpan.FromSeconds(20));
+        return f;
+    }
+
+    /// <summary>Starts a node from production HOCON; used by StartAsync and by restart-scenarios.</summary>
+    public ActorSystem StartNode(int port, string role, TimeSpan? stableAfter = null)
+    {
+        var nodeOptions = new NodeOptions { Role = role, NodeHostname = "127.0.0.1", RemotingPort = port };
+        var clusterOptions = new ClusterOptions
+        {
+            SeedNodes = new List<string>
+            {
+                $"akka.tcp://scadabridge@127.0.0.1:{PortA}",
+                $"akka.tcp://scadabridge@127.0.0.1:{PortB}",
+            },
+            SplitBrainResolverStrategy = "keep-oldest",
+            StableAfter = stableAfter ?? TimeSpan.FromSeconds(3),
+            HeartbeatInterval = TimeSpan.FromMilliseconds(500),
+            FailureDetectionThreshold = TimeSpan.FromSeconds(2),
+            MinNrOfMembers = 1,
+            DownIfAlone = true,
+        };
+        var hocon = AkkaHostedService.BuildHocon(
+            nodeOptions, clusterOptions, new[] { role },
+            TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(3));
+        // Crash simulation: Terminate() must NOT run CoordinatedShutdown
+        // (no Leave gossip) or the test degenerates to the graceful path.
+        var config = ConfigurationFactory
+            .ParseString("akka.coordinated-shutdown.run-by-actor-system-terminate = off")
+            .WithFallback(ConfigurationFactory.ParseString(hocon));
+        return ActorSystem.Create("scadabridge", config);
+    }
+
+    /// <summary>Hard-crash a node: abrupt terminate, no cluster leave.</summary>
+    public static Task CrashNode(ActorSystem node) => node.Terminate();
+
+    public static async Task WaitForMembersUp(ActorSystem system, int count, TimeSpan timeout)
+    {
+        var cluster = Akka.Cluster.Cluster.Get(system);
+        var deadline = DateTime.UtcNow + timeout;
+        while (DateTime.UtcNow < deadline)
+        {
+            if (cluster.State.Members.Count(m => m.Status == MemberStatus.Up) == count
+                && !cluster.State.Unreachable.Any())
+                return;
+            await Task.Delay(200);
+        }
+        throw new TimeoutException(
+            $"Cluster on {cluster.SelfAddress} did not reach {count} Up members within {timeout}. " +
+            $"Members: [{string.Join(", ", cluster.State.Members)}], " +
+            $"Unreachable: [{string.Join(", ", cluster.State.Unreachable)}]");
+    }
+
+    public static async Task WaitForMemberRemoved(ActorSystem survivor, Address removed, TimeSpan timeout)
+    {
+        var cluster = Akka.Cluster.Cluster.Get(survivor);
+        var deadline = DateTime.UtcNow + timeout;
+        while (DateTime.UtcNow < deadline)
+        {
+            if (cluster.State.Members.All(m => m.Address != removed)
+                && cluster.State.Unreachable.All(m => m.Address != removed))
+                return;
+            await Task.Delay(200);
+        }
+        throw new TimeoutException($"Member {removed} was never removed from {cluster.SelfAddress}'s view — SBR did not down it.");
+    }
+
+    private static int GetFreeTcpPort()
+    {
+        var listener = new System.Net.Sockets.TcpListener(System.Net.IPAddress.Loopback, 0);
+        listener.Start();
+        var port = ((System.Net.IPEndPoint)listener.LocalEndpoint).Port;
+        listener.Stop();
+        return port;
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        foreach (var sys in new[] { NodeA, NodeB })
+        {
+            if (sys is { WhenTerminated.IsCompleted: false })
+            {
+                try { await sys.Terminate().WaitAsync(TimeSpan.FromSeconds(10)); } catch { /* teardown */ }
+            }
+        }
+    }
+}
diff --git a/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixtureTests.cs b/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixtureTests.cs
new file mode 100644
index 00000000..abf71bcd
--- /dev/null
+++ b/tests/ZB.MOM.WW.ScadaBridge.IntegrationTests/Cluster/TwoNodeClusterFixtureTests.cs
@@ -0,0 +1,18 @@
+using Xunit;
+
+namespace ZB.MOM.WW.ScadaBridge.IntegrationTests.Cluster;
+
+public class TwoNodeClusterFixtureTests
+{
+    [Fact]
+    public async Task Fixture_FormsTwoNodeCluster_NodeAIsOldest()
+    {
+        await using var cluster = await TwoNodeClusterFixture.StartAsync();
+        var a = Akka.Cluster.Cluster.Get(cluster.NodeA);
+        var b = Akka.Cluster.Cluster.Get(cluster.NodeB);
+        Assert.Equal(2, a.State.Members.Count);
+        Assert.Equal(2, b.State.Members.Count);
+        // NodeA started first => oldest (the singleton host).
+        Assert.True(a.SelfMember.IsOlderThan(b.State.Members.First(m => m.Address == b.SelfAddress)));
+    }
+}