diff --git a/.github/workflows/test-suite.yml b/.github/workflows/test-suite.yml
index 0f9689ea93..ae3a176500 100644
--- a/.github/workflows/test-suite.yml
+++ b/.github/workflows/test-suite.yml
@@ -49,12 +49,21 @@ jobs:
     - uses: actions/checkout@v1
     - name: Build the root Dockerfile
       run: docker build .
-  simulator-ubuntu:
+  eth1-simulator-ubuntu:
     runs-on: ubuntu-latest
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
     - name: Install ganache-cli
       run: sudo npm install -g ganache-cli
-    - name: Run the beacon chain sim
-      run: cargo run --release --bin simulator beacon-chain-sim
+    - name: Run the beacon chain sim that starts from an eth1 contract
+      run: cargo run --release --bin simulator eth1-sim
+  no-eth1-simulator-ubuntu:
+    runs-on: ubuntu-latest
+    needs: cargo-fmt
+    steps:
+    - uses: actions/checkout@v1
+    - name: Install ganache-cli
+      run: sudo npm install -g ganache-cli
+    - name: Run the beacon chain sim without an eth1 connection
+      run: cargo run --release --bin simulator no-eth1-sim
diff --git a/tests/simulator/src/cli.rs b/tests/simulator/src/cli.rs
index 93c8cb051b..95c4bcc19f 100644
--- a/tests/simulator/src/cli.rs
+++ b/tests/simulator/src/cli.rs
@@ -6,7 +6,7 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
         .author("Sigma Prime <contact@sigmaprime.io>")
         .about("Options for interacting with simulator")
         .subcommand(
-            SubCommand::with_name("beacon-chain-sim")
+            SubCommand::with_name("eth1-sim")
             .about(
                 "Lighthouse Beacon Chain Simulator creates `n` beacon node and validator clients, \
                     each with `v` validators. A deposit contract is deployed at the start of the \
@@ -22,17 +22,48 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
                         .short("n")
                         .long("nodes")
                         .takes_value(true)
-                        .help("Number of beacon nodes (default 4)"))
+                        .default_value("4")
+                        .help("Number of beacon nodes"))
                     .arg(Arg::with_name("validators_per_node")
                         .short("v")
                         .long("validators_per_node")
                         .takes_value(true)
-                        .help("Number of validators (default 20)"))
+                        .default_value("20")
+                        .help("Number of validators"))
                     .arg(Arg::with_name("speed_up_factor")
                         .short("s")
                         .long("speed_up_factor")
                         .takes_value(true)
-                        .help("Speed up factor (default 4)"))
+                        .default_value("4")
+                        .help("Speed up factor"))
+                    .arg(Arg::with_name("end_after_checks")
+                        .short("e")
+                        .long("end_after_checks")
+                        .takes_value(false)
+                        .help("End after checks (default true)"))
+        )
+        .subcommand(
+            SubCommand::with_name("no-eth1-sim")
+            .about("Runs a simulator that bypasses the eth1 chain. Useful for faster testing of
+                components that don't rely upon eth1")
+                    .arg(Arg::with_name("nodes")
+                        .short("n")
+                        .long("nodes")
+                        .takes_value(true)
+                        .default_value("4")
+                        .help("Number of beacon nodes"))
+                    .arg(Arg::with_name("validators_per_node")
+                        .short("v")
+                        .long("validators_per_node")
+                        .takes_value(true)
+                        .default_value("20")
+                        .help("Number of validators"))
+                    .arg(Arg::with_name("speed_up_factor")
+                        .short("s")
+                        .long("speed_up_factor")
+                        .takes_value(true)
+                        .default_value("4")
+                        .help("Speed up factor"))
                     .arg(Arg::with_name("end_after_checks")
                         .short("e")
                         .long("end_after_checks")
diff --git a/tests/simulator/src/eth1_sim.rs b/tests/simulator/src/eth1_sim.rs
new file mode 100644
index 0000000000..3413701c5d
--- /dev/null
+++ b/tests/simulator/src/eth1_sim.rs
@@ -0,0 +1,208 @@
+use crate::{checks, LocalNetwork, E};
+use clap::ArgMatches;
+use eth1_test_rig::GanacheEth1Instance;
+use futures::{future, stream, Future, Stream};
+use node_test_rig::{
+    environment::EnvironmentBuilder, testing_client_config, ClientGenesis, ValidatorConfig,
+};
+use std::net::{IpAddr, Ipv4Addr};
+use std::time::{Duration, Instant};
+use tokio::timer::Interval;
+
+pub fn run_eth1_sim(matches: &ArgMatches) -> Result<(), String> {
+    let node_count = value_t!(matches, "nodes", usize).expect("missing nodes default");
+    let validators_per_node = value_t!(matches, "validators_per_node", usize)
+        .expect("missing validators_per_node default");
+    let speed_up_factor =
+        value_t!(matches, "speed_up_factor", u64).expect("missing speed_up_factor default");
+    let mut end_after_checks = true;
+    if matches.is_present("end_after_checks") {
+        end_after_checks = false;
+    }
+
+    println!("Beacon Chain Simulator:");
+    println!(" nodes:{}", node_count);
+    println!(" validators_per_node:{}", validators_per_node);
+    println!(" end_after_checks:{}", end_after_checks);
+
+    let log_level = "debug";
+    let log_format = None;
+
+    let mut env = EnvironmentBuilder::minimal()
+        .async_logger(log_level, log_format)?
+        .multi_threaded_tokio_runtime()?
+        .build()?;
+
+    let eth1_block_time = Duration::from_millis(15_000 / speed_up_factor);
+
+    let spec = &mut env.eth2_config.spec;
+
+    spec.milliseconds_per_slot /= speed_up_factor;
+    spec.eth1_follow_distance = 16;
+    spec.min_genesis_delay = eth1_block_time.as_secs() * spec.eth1_follow_distance * 2;
+    spec.min_genesis_time = 0;
+    spec.min_genesis_active_validator_count = 64;
+    spec.seconds_per_eth1_block = 1;
+
+    let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
+    let initial_validator_count = spec.min_genesis_active_validator_count as usize;
+    let total_validator_count = validators_per_node * node_count;
+    let deposit_amount = env.eth2_config.spec.max_effective_balance;
+
+    let context = env.core_context();
+    let executor = context.executor.clone();
+
+    let future = GanacheEth1Instance::new()
+        /*
+         * Deploy the deposit contract, spawn tasks to keep creating new blocks and deposit
+         * validators.
+         */
+        .map(move |ganache_eth1_instance| {
+            let deposit_contract = ganache_eth1_instance.deposit_contract;
+            let ganache = ganache_eth1_instance.ganache;
+            let eth1_endpoint = ganache.endpoint();
+            let deposit_contract_address = deposit_contract.address();
+
+            // Start a timer that produces eth1 blocks on an interval.
+            executor.spawn(
+                Interval::new(Instant::now(), eth1_block_time)
+                    .map_err(|_| eprintln!("Eth1 block timer failed"))
+                    .for_each(move |_| ganache.evm_mine().map_err(|_| ()))
+                    .map_err(|_| eprintln!("Eth1 evm_mine failed"))
+                    .map(|_| ()),
+            );
+
+            // Submit deposits to the deposit contract.
+            executor.spawn(
+                stream::unfold(0..total_validator_count, move |mut iter| {
+                    iter.next().map(|i| {
+                        println!("Submitting deposit for validator {}...", i);
+                        deposit_contract
+                            .deposit_deterministic_async::<E>(i, deposit_amount)
+                            .map(|_| ((), iter))
+                    })
+                })
+                .collect()
+                .map(|_| ())
+                .map_err(|e| eprintln!("Error submitting deposit: {}", e)),
+            );
+
+            let mut beacon_config = testing_client_config();
+
+            beacon_config.genesis = ClientGenesis::DepositContract;
+            beacon_config.eth1.endpoint = eth1_endpoint;
+            beacon_config.eth1.deposit_contract_address = deposit_contract_address;
+            beacon_config.eth1.deposit_contract_deploy_block = 0;
+            beacon_config.eth1.lowest_cached_block_number = 0;
+            beacon_config.eth1.follow_distance = 1;
+            beacon_config.dummy_eth1_backend = false;
+            beacon_config.sync_eth1_chain = true;
+
+            beacon_config.network.enr_address = Some(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
+
+            beacon_config
+        })
+        /*
+         * Create a new `LocalNetwork` with one beacon node.
+         */
+        .and_then(move |beacon_config| {
+            LocalNetwork::new(context, beacon_config.clone())
+                .map(|network| (network, beacon_config))
+        })
+        /*
+         * One by one, add beacon nodes to the network.
+         */
+        .and_then(move |(network, beacon_config)| {
+            let network_1 = network.clone();
+
+            stream::unfold(0..node_count - 1, move |mut iter| {
+                iter.next().map(|_| {
+                    network_1
+                        .add_beacon_node(beacon_config.clone())
+                        .map(|()| ((), iter))
+                })
+            })
+            .collect()
+            .map(|_| network)
+        })
+        /*
+         * One by one, add validator clients to the network. Each validator client is attached to
+         * a single corresponding beacon node.
+         */
+        .and_then(move |network| {
+            let network_1 = network.clone();
+
+            // Note: presently the validator client future will only resolve once genesis time
+            // occurs. This is great for this scenario, but likely to change in the future.
+            //
+            // If the validator client future behaviour changes, we would need to add a new future
+            // that delays until genesis. Otherwise, all of the checks that start in the next
+            // future will start too early.
+
+            stream::unfold(0..node_count, move |mut iter| {
+                iter.next().map(|i| {
+                    let indices = (i * validators_per_node..(i + 1) * validators_per_node)
+                        .collect::<Vec<_>>();
+
+                    network_1
+                        .add_validator_client(ValidatorConfig::default(), i, indices)
+                        .map(|()| ((), iter))
+                })
+            })
+            .collect()
+            .map(|_| network)
+        })
+        /*
+         * Start the processes that will run checks on the network as it runs.
+         */
+        .and_then(move |network| {
+            // The `final_future` either completes immediately or never completes, depending on the value
+            // of `end_after_checks`.
+            let final_future: Box<dyn Future<Item = (), Error = String> + Send> =
+                if end_after_checks {
+                    Box::new(future::ok(()).map_err(|()| "".to_string()))
+                } else {
+                    Box::new(future::empty().map_err(|()| "".to_string()))
+                };
+
+            future::ok(())
+                // Check that the chain finalizes at the first given opportunity.
+                .join(checks::verify_first_finalization(
+                    network.clone(),
+                    slot_duration,
+                ))
+                // Check that the chain starts with the expected validator count.
+                .join(checks::verify_initial_validator_count(
+                    network.clone(),
+                    slot_duration,
+                    initial_validator_count,
+                ))
+                // Check that validators greater than `spec.min_genesis_active_validator_count` are
+                // onboarded at the first possible opportunity.
+                .join(checks::verify_validator_onboarding(
+                    network.clone(),
+                    slot_duration,
+                    total_validator_count,
+                ))
+                // End now or run forever, depending on the `end_after_checks` flag.
+                .join(final_future)
+                .map(|_| network)
+        })
+        /*
+         * End the simulation by dropping the network. This will kill all running beacon nodes and
+         * validator clients.
+         */
+        .map(|network| {
+            println!(
+                "Simulation complete. Finished with {} beacon nodes and {} validator clients",
+                network.beacon_node_count(),
+                network.validator_client_count()
+            );
+
+            // Be explicit about dropping the network, as this kills all the nodes. This ensures
+            // all the checks have adequate time to pass.
+            drop(network)
+        });
+
+    env.runtime().block_on(future)
+}
diff --git a/tests/simulator/src/main.rs b/tests/simulator/src/main.rs
index 85be8ccae0..742f110874 100644
--- a/tests/simulator/src/main.rs
+++ b/tests/simulator/src/main.rs
@@ -18,21 +18,14 @@ extern crate clap;
 
 mod checks;
 mod cli;
+mod eth1_sim;
 mod local_network;
+mod no_eth1_sim;
 mod sync_sim;
 
-use clap::ArgMatches;
 use cli::cli_app;
 use env_logger::{Builder, Env};
-use eth1_test_rig::GanacheEth1Instance;
-use futures::{future, stream, Future, Stream};
 use local_network::LocalNetwork;
-use node_test_rig::{
-    environment::EnvironmentBuilder, testing_client_config, ClientGenesis, ValidatorConfig,
-};
-use std::time::{Duration, Instant};
-use sync_sim::*;
-use tokio::timer::Interval;
 use types::MinimalEthSpec;
 
 pub type E = MinimalEthSpec;
@@ -43,14 +36,21 @@ fn main() {
 
     let matches = cli_app().get_matches();
     match matches.subcommand() {
-        ("beacon-chain-sim", Some(matches)) => match run_beacon_chain_sim(matches) {
+        ("eth1-sim", Some(matches)) => match eth1_sim::run_eth1_sim(matches) {
             Ok(()) => println!("Simulation exited successfully"),
             Err(e) => {
                 eprintln!("Simulation exited with error: {}", e);
                 std::process::exit(1)
             }
         },
-        ("syncing-sim", Some(matches)) => match run_syncing_sim(matches) {
+        ("no-eth1-sim", Some(matches)) => match no_eth1_sim::run_no_eth1_sim(matches) {
+            Ok(()) => println!("Simulation exited successfully"),
+            Err(e) => {
+                eprintln!("Simulation exited with error: {}", e);
+                std::process::exit(1)
+            }
+        },
+        ("syncing-sim", Some(matches)) => match sync_sim::run_syncing_sim(matches) {
             Ok(()) => println!("Simulation exited successfully"),
             Err(e) => {
                 eprintln!("Simulation exited with error: {}", e);
@@ -63,319 +63,3 @@ fn main() {
         }
     }
 }
-
-fn run_beacon_chain_sim(matches: &ArgMatches) -> Result<(), String> {
-    let nodes = value_t!(matches, "nodes", usize).unwrap_or(4);
-    let validators_per_node = value_t!(matches, "validators_per_node", usize).unwrap_or(20);
-    let speed_up_factor = value_t!(matches, "nodes", u64).unwrap_or(4);
-    let mut end_after_checks = true;
-    if matches.is_present("end_after_checks") {
-        end_after_checks = false;
-    }
-
-    println!("Beacon Chain Simulator:");
-    println!(" nodes:{}", nodes);
-    println!(" validators_per_node:{}", validators_per_node);
-    println!(" end_after_checks:{}", end_after_checks);
-
-    let log_level = "debug";
-    let log_format = None;
-
-    beacon_chain_sim(
-        nodes,
-        validators_per_node,
-        speed_up_factor,
-        log_level,
-        log_format,
-        end_after_checks,
-    )
-}
-
-fn run_syncing_sim(matches: &ArgMatches) -> Result<(), String> {
-    let initial_delay = value_t!(matches, "initial_delay", u64).unwrap_or(50);
-    let sync_delay = value_t!(matches, "sync_delay", u64).unwrap_or(10);
-    let speed_up_factor = value_t!(matches, "speedup", u64).unwrap_or(15);
-    let strategy = value_t!(matches, "strategy", String).unwrap_or("all".into());
-
-    println!("Syncing Simulator:");
-    println!(" initial_delay:{}", initial_delay);
-    println!(" sync delay:{}", sync_delay);
-    println!(" speed up factor:{}", speed_up_factor);
-    println!(" strategy:{}", strategy);
-
-    let log_level = "debug";
-    let log_format = None;
-
-    syncing_sim(
-        speed_up_factor,
-        initial_delay,
-        sync_delay,
-        strategy,
-        log_level,
-        log_format,
-    )
-}
-
-fn syncing_sim(
-    speed_up_factor: u64,
-    initial_delay: u64,
-    sync_delay: u64,
-    strategy: String,
-    log_level: &str,
-    log_format: Option<&str>,
-) -> Result<(), String> {
-    let mut env = EnvironmentBuilder::minimal()
-        .async_logger(log_level, log_format)?
-        .multi_threaded_tokio_runtime()?
-        .build()?;
-
-    let spec = &mut env.eth2_config.spec;
-    let end_after_checks = true;
-
-    spec.milliseconds_per_slot = spec.milliseconds_per_slot / speed_up_factor;
-    spec.min_genesis_time = 0;
-    spec.min_genesis_active_validator_count = 16;
-
-    let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
-
-    let context = env.core_context();
-    let beacon_config = testing_client_config();
-    let num_validators = 8;
-    let future = LocalNetwork::new(context, beacon_config.clone())
-        /*
-         * Add a validator client which handles all validators from the genesis state.
-         */
-        .and_then(move |network| {
-            network
-                .add_validator_client(ValidatorConfig::default(), 0, (0..num_validators).collect())
-                .map(|_| network)
-        })
-        /*
-         * Start the processes that will run checks on the network as it runs.
-         */
-        .and_then(move |network| {
-            // The `final_future` either completes immediately or never completes, depending on the value
-            // of `end_after_checks`.
-            let final_future: Box<dyn Future<Item = (), Error = String> + Send> =
-                if end_after_checks {
-                    Box::new(future::ok(()).map_err(|()| "".to_string()))
-                } else {
-                    Box::new(future::empty().map_err(|()| "".to_string()))
-                };
-
-            future::ok(())
-                // Check all syncing strategies one after other.
-                .join(pick_strategy(
-                    &strategy,
-                    network.clone(),
-                    beacon_config.clone(),
-                    slot_duration,
-                    initial_delay,
-                    sync_delay,
-                ))
-                .join(final_future)
-                .map(|_| network)
-        })
-        /*
-         * End the simulation by dropping the network. This will kill all running beacon nodes and
-         * validator clients.
-         */
-        .map(|network| {
-            println!(
-                "Simulation complete. Finished with {} beacon nodes and {} validator clients",
-                network.beacon_node_count(),
-                network.validator_client_count()
-            );
-
-            // Be explicit about dropping the network, as this kills all the nodes. This ensures
-            // all the checks have adequate time to pass.
-            drop(network)
-        });
-
-    env.runtime().block_on(future)
-}
-
-fn beacon_chain_sim(
-    node_count: usize,
-    validators_per_node: usize,
-    speed_up_factor: u64,
-    log_level: &str,
-    log_format: Option<&str>,
-    end_after_checks: bool,
-) -> Result<(), String> {
-    let mut env = EnvironmentBuilder::minimal()
-        .async_logger(log_level, log_format)?
-        .multi_threaded_tokio_runtime()?
-        .build()?;
-
-    let eth1_block_time = Duration::from_millis(15_000 / speed_up_factor);
-
-    let spec = &mut env.eth2_config.spec;
-
-    spec.milliseconds_per_slot /= speed_up_factor;
-    spec.eth1_follow_distance = 16;
-    spec.min_genesis_delay = eth1_block_time.as_secs() * spec.eth1_follow_distance * 2;
-    spec.min_genesis_time = 0;
-    spec.min_genesis_active_validator_count = 64;
-    spec.seconds_per_eth1_block = 1;
-
-    let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
-    let initial_validator_count = spec.min_genesis_active_validator_count as usize;
-    let total_validator_count = validators_per_node * node_count;
-    let deposit_amount = env.eth2_config.spec.max_effective_balance;
-
-    let context = env.core_context();
-    let executor = context.executor.clone();
-
-    let future = GanacheEth1Instance::new()
-        /*
-         * Deploy the deposit contract, spawn tasks to keep creating new blocks and deposit
-         * validators.
-         */
-        .map(move |ganache_eth1_instance| {
-            let deposit_contract = ganache_eth1_instance.deposit_contract;
-            let ganache = ganache_eth1_instance.ganache;
-            let eth1_endpoint = ganache.endpoint();
-            let deposit_contract_address = deposit_contract.address();
-
-            // Start a timer that produces eth1 blocks on an interval.
-            executor.spawn(
-                Interval::new(Instant::now(), eth1_block_time)
-                    .map_err(|_| eprintln!("Eth1 block timer failed"))
-                    .for_each(move |_| ganache.evm_mine().map_err(|_| ()))
-                    .map_err(|_| eprintln!("Eth1 evm_mine failed"))
-                    .map(|_| ()),
-            );
-
-            // Submit deposits to the deposit contract.
-            executor.spawn(
-                stream::unfold(0..total_validator_count, move |mut iter| {
-                    iter.next().map(|i| {
-                        println!("Submitting deposit for validator {}...", i);
-                        deposit_contract
-                            .deposit_deterministic_async::<E>(i, deposit_amount)
-                            .map(|_| ((), iter))
-                    })
-                })
-                .collect()
-                .map(|_| ())
-                .map_err(|e| eprintln!("Error submitting deposit: {}", e)),
-            );
-
-            let mut beacon_config = testing_client_config();
-
-            beacon_config.genesis = ClientGenesis::DepositContract;
-            beacon_config.eth1.endpoint = eth1_endpoint;
-            beacon_config.eth1.deposit_contract_address = deposit_contract_address;
-            beacon_config.eth1.deposit_contract_deploy_block = 0;
-            beacon_config.eth1.lowest_cached_block_number = 0;
-            beacon_config.eth1.follow_distance = 1;
-            beacon_config.dummy_eth1_backend = false;
-            beacon_config.sync_eth1_chain = true;
-
-            beacon_config
-        })
-        /*
-         * Create a new `LocalNetwork` with one beacon node.
-         */
-        .and_then(move |beacon_config| {
-            LocalNetwork::new(context, beacon_config.clone())
-                .map(|network| (network, beacon_config))
-        })
-        /*
-         * One by one, add beacon nodes to the network.
-         */
-        .and_then(move |(network, beacon_config)| {
-            let network_1 = network.clone();
-
-            stream::unfold(0..node_count - 1, move |mut iter| {
-                iter.next().map(|_| {
-                    network_1
-                        .add_beacon_node(beacon_config.clone())
-                        .map(|()| ((), iter))
-                })
-            })
-            .collect()
-            .map(|_| network)
-        })
-        /*
-         * One by one, add validator clients to the network. Each validator client is attached to
-         * a single corresponding beacon node.
-         */
-        .and_then(move |network| {
-            let network_1 = network.clone();
-
-            // Note: presently the validator client future will only resolve once genesis time
-            // occurs. This is great for this scenario, but likely to change in the future.
-            //
-            // If the validator client future behaviour changes, we would need to add a new future
-            // that delays until genesis. Otherwise, all of the checks that start in the next
-            // future will start too early.
-
-            stream::unfold(0..node_count, move |mut iter| {
-                iter.next().map(|i| {
-                    let indices = (i * validators_per_node..(i + 1) * validators_per_node)
-                        .collect::<Vec<_>>();
-
-                    network_1
-                        .add_validator_client(ValidatorConfig::default(), i, indices)
-                        .map(|()| ((), iter))
-                })
-            })
-            .collect()
-            .map(|_| network)
-        })
-        /*
-         * Start the processes that will run checks on the network as it runs.
-         */
-        .and_then(move |network| {
-            // The `final_future` either completes immediately or never completes, depending on the value
-            // of `end_after_checks`.
-            let final_future: Box<dyn Future<Item = (), Error = String> + Send> =
-                if end_after_checks {
-                    Box::new(future::ok(()).map_err(|()| "".to_string()))
-                } else {
-                    Box::new(future::empty().map_err(|()| "".to_string()))
-                };
-
-            future::ok(())
-                // Check that the chain finalizes at the first given opportunity.
-                .join(checks::verify_first_finalization(
-                    network.clone(),
-                    slot_duration,
-                ))
-                // Check that the chain starts with the expected validator count.
-                .join(checks::verify_initial_validator_count(
-                    network.clone(),
-                    slot_duration,
-                    initial_validator_count,
-                ))
-                // Check that validators greater than `spec.min_genesis_active_validator_count` are
-                // onboarded at the first possible opportunity.
-                .join(checks::verify_validator_onboarding(
-                    network.clone(),
-                    slot_duration,
-                    total_validator_count,
-                ))
-                // End now or run forever, depending on the `end_after_checks` flag.
-                .join(final_future)
-                .map(|_| network)
-        })
-        /*
-         * End the simulation by dropping the network. This will kill all running beacon nodes and
-         * validator clients.
-         */
-        .map(|network| {
-            println!(
-                "Simulation complete. Finished with {} beacon nodes and {} validator clients",
-                network.beacon_node_count(),
-                network.validator_client_count()
-            );
-
-            // Be explicit about dropping the network, as this kills all the nodes. This ensures
-            // all the checks have adequate time to pass.
-            drop(network)
-        });
-
-    env.runtime().block_on(future)
-}
diff --git a/tests/simulator/src/no_eth1_sim.rs b/tests/simulator/src/no_eth1_sim.rs
new file mode 100644
index 0000000000..b4d233909f
--- /dev/null
+++ b/tests/simulator/src/no_eth1_sim.rs
@@ -0,0 +1,150 @@
+use crate::{checks, LocalNetwork};
+use clap::ArgMatches;
+use futures::{future, stream, Future, Stream};
+use node_test_rig::{
+    environment::EnvironmentBuilder, testing_client_config, ClientGenesis, ValidatorConfig,
+};
+use std::net::{IpAddr, Ipv4Addr};
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
+
+pub fn run_no_eth1_sim(matches: &ArgMatches) -> Result<(), String> {
+    let node_count = value_t!(matches, "nodes", usize).expect("missing nodes default");
+    let validators_per_node = value_t!(matches, "validators_per_node", usize)
+        .expect("missing validators_per_node default");
+    let speed_up_factor =
+        value_t!(matches, "speed_up_factor", u64).expect("missing speed_up_factor default");
+    let mut end_after_checks = true;
+    if matches.is_present("end_after_checks") {
+        end_after_checks = false;
+    }
+
+    println!("Beacon Chain Simulator:");
+    println!(" nodes:{}", node_count);
+    println!(" validators_per_node:{}", validators_per_node);
+    println!(" end_after_checks:{}", end_after_checks);
+
+    let log_level = "debug";
+    let log_format = None;
+
+    let mut env = EnvironmentBuilder::mainnet()
+        .async_logger(log_level, log_format)?
+        .multi_threaded_tokio_runtime()?
+        .build()?;
+
+    let eth1_block_time = Duration::from_millis(15_000 / speed_up_factor);
+
+    let spec = &mut env.eth2_config.spec;
+
+    spec.milliseconds_per_slot /= speed_up_factor;
+    spec.eth1_follow_distance = 16;
+    spec.min_genesis_delay = eth1_block_time.as_secs() * spec.eth1_follow_distance * 2;
+    spec.min_genesis_time = 0;
+    spec.min_genesis_active_validator_count = 64;
+    spec.seconds_per_eth1_block = 1;
+
+    let genesis_time = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_err(|_| "should get system time")?
+        + Duration::from_secs(5);
+
+    let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
+    let total_validator_count = validators_per_node * node_count;
+
+    let context = env.core_context();
+
+    let mut beacon_config = testing_client_config();
+
+    beacon_config.genesis = ClientGenesis::Interop {
+        validator_count: total_validator_count,
+        genesis_time: genesis_time.as_secs(),
+    };
+    beacon_config.dummy_eth1_backend = true;
+    beacon_config.sync_eth1_chain = true;
+
+    beacon_config.network.enr_address = Some(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
+
+    let future = LocalNetwork::new(context, beacon_config.clone())
+        /*
+         * One by one, add beacon nodes to the network.
+         */
+        .and_then(move |network| {
+            let network_1 = network.clone();
+
+            stream::unfold(0..node_count - 1, move |mut iter| {
+                iter.next().map(|_| {
+                    network_1
+                        .add_beacon_node(beacon_config.clone())
+                        .map(|()| ((), iter))
+                })
+            })
+            .collect()
+            .map(|_| network)
+        })
+        /*
+         * One by one, add validator clients to the network. Each validator client is attached to
+         * a single corresponding beacon node.
+         */
+        .and_then(move |network| {
+            let network_1 = network.clone();
+
+            // Note: presently the validator client future will only resolve once genesis time
+            // occurs. This is great for this scenario, but likely to change in the future.
+            //
+            // If the validator client future behaviour changes, we would need to add a new future
+            // that delays until genesis. Otherwise, all of the checks that start in the next
+            // future will start too early.
+
+            stream::unfold(0..node_count, move |mut iter| {
+                iter.next().map(|i| {
+                    let indices = (i * validators_per_node..(i + 1) * validators_per_node)
+                        .collect::<Vec<_>>();
+
+                    network_1
+                        .add_validator_client(ValidatorConfig::default(), i, indices)
+                        .map(|()| ((), iter))
+                })
+            })
+            .collect()
+            .map(|_| network)
+        })
+        /*
+         * Start the processes that will run checks on the network as it runs.
+         */
+        .and_then(move |network| {
+            // The `final_future` either completes immediately or never completes, depending on the value
+            // of `end_after_checks`.
+            let final_future: Box<dyn Future<Item = (), Error = String> + Send> =
+                if end_after_checks {
+                    Box::new(future::ok(()).map_err(|()| "".to_string()))
+                } else {
+                    Box::new(future::empty().map_err(|()| "".to_string()))
+                };
+
+            future::ok(())
+                // Check that the chain finalizes at the first given opportunity.
+                .join(checks::verify_first_finalization(
+                    network.clone(),
+                    slot_duration,
+                ))
+                // End now or run forever, depending on the `end_after_checks` flag.
+                .join(final_future)
+                .map(|_| network)
+        })
+        /*
+         * End the simulation by dropping the network. This will kill all running beacon nodes and
+         * validator clients.
+         */
+        .map(|network| {
+            println!(
+                "Simulation complete. Finished with {} beacon nodes and {} validator clients",
+                network.beacon_node_count(),
+                network.validator_client_count()
+            );
+
+            // Be explicit about dropping the network, as this kills all the nodes. This ensures
+            // all the checks have adequate time to pass.
+            drop(network)
+        });
+
+    env.runtime().block_on(future)
+}
diff --git a/tests/simulator/src/sync_sim.rs b/tests/simulator/src/sync_sim.rs
index 6c18406b6e..68dec54f90 100644
--- a/tests/simulator/src/sync_sim.rs
+++ b/tests/simulator/src/sync_sim.rs
@@ -1,10 +1,116 @@
 use crate::checks::{epoch_delay, verify_all_finalized_at};
 use crate::local_network::LocalNetwork;
-use futures::{Future, IntoFuture};
+use clap::ArgMatches;
+use futures::{future, Future, IntoFuture};
 use node_test_rig::ClientConfig;
+use node_test_rig::{environment::EnvironmentBuilder, testing_client_config, ValidatorConfig};
 use std::time::Duration;
 use types::{Epoch, EthSpec};
 
+pub fn run_syncing_sim(matches: &ArgMatches) -> Result<(), String> {
+    let initial_delay = value_t!(matches, "initial_delay", u64).unwrap_or(50);
+    let sync_delay = value_t!(matches, "sync_delay", u64).unwrap_or(10);
+    let speed_up_factor = value_t!(matches, "speedup", u64).unwrap_or(15);
+    let strategy = value_t!(matches, "strategy", String).unwrap_or("all".into());
+
+    println!("Syncing Simulator:");
+    println!(" initial_delay:{}", initial_delay);
+    println!(" sync delay:{}", sync_delay);
+    println!(" speed up factor:{}", speed_up_factor);
+    println!(" strategy:{}", strategy);
+
+    let log_level = "debug";
+    let log_format = None;
+
+    syncing_sim(
+        speed_up_factor,
+        initial_delay,
+        sync_delay,
+        strategy,
+        log_level,
+        log_format,
+    )
+}
+
+fn syncing_sim(
+    speed_up_factor: u64,
+    initial_delay: u64,
+    sync_delay: u64,
+    strategy: String,
+    log_level: &str,
+    log_format: Option<&str>,
+) -> Result<(), String> {
+    let mut env = EnvironmentBuilder::minimal()
+        .async_logger(log_level, log_format)?
+        .multi_threaded_tokio_runtime()?
+        .build()?;
+
+    let spec = &mut env.eth2_config.spec;
+    let end_after_checks = true;
+
+    spec.milliseconds_per_slot = spec.milliseconds_per_slot / speed_up_factor;
+    spec.min_genesis_time = 0;
+    spec.min_genesis_active_validator_count = 16;
+
+    let slot_duration = Duration::from_millis(spec.milliseconds_per_slot);
+    let context = env.core_context();
+    let num_validators = 8;
+    let beacon_config = testing_client_config();
+
+    let future = LocalNetwork::new(context, beacon_config.clone())
+        /*
+         * Add a validator client which handles all validators from the genesis state.
+         */
+        .and_then(move |network| {
+            network
+                .add_validator_client(ValidatorConfig::default(), 0, (0..num_validators).collect())
+                .map(|_| network)
+        })
+        /*
+         * Start the processes that will run checks on the network as it runs.
+         */
+        .and_then(move |network| {
+            // The `final_future` either completes immediately or never completes, depending on the value
+            // of `end_after_checks`.
+            let final_future: Box<dyn Future<Item = (), Error = String> + Send> =
+                if end_after_checks {
+                    Box::new(future::ok(()).map_err(|()| "".to_string()))
+                } else {
+                    Box::new(future::empty().map_err(|()| "".to_string()))
+                };
+
+            future::ok(())
+                // Check all syncing strategies one after other.
+                .join(pick_strategy(
+                    &strategy,
+                    network.clone(),
+                    beacon_config.clone(),
+                    slot_duration,
+                    initial_delay,
+                    sync_delay,
+                ))
+                .join(final_future)
+                .map(|_| network)
+        })
+        /*
+         * End the simulation by dropping the network. This will kill all running beacon nodes and
+         * validator clients.
+         */
+        .map(|network| {
+            println!(
+                "Simulation complete. Finished with {} beacon nodes and {} validator clients",
+                network.beacon_node_count(),
+                network.validator_client_count()
+            );
+
+            // Be explicit about dropping the network, as this kills all the nodes. This ensures
+            // all the checks have adequate time to pass.
+            drop(network)
+        });
+
+    env.runtime().block_on(future)
+}
+
 pub fn pick_strategy<E: EthSpec>(
     strategy: &str,
     network: LocalNetwork<E>,